If you don't know what this is for, LEAVE NOW!!!

For Universities, I have not figured out how to add more characters, so all you can do is delete. The easiest is, of course, to just delete every character. (ETA: I now know how to do it, but this tutorial isn't the place for that info).

Open C:\Program Files\EA GAMES\The Sims 2 University\TSData\Res\NeighborhoodTemplate and open the U001, U002, and U003 folders. Open the Characters folder that is inside each one. Delete all the files from the Characters folders. Next, inside each U00# folder is a U00#_Neighborhood file. Open that in SimPE. Click on Sim Descriptions on the left side and then delete all the unknowns... but make sure your version of SimPE correctly identifies Grim Reaper, Hula Zombie, P Tech, and Therapist, instead of marking them as unknown, because you would not want to delete them. I'm pretty sure there's just these four files in each neighborhood that should be left alone.

Now let's take care of some dangling Sim Wants/Fears and Relations.
Open the U00#_Neighborhood file and choose Sim Relations on the left-hand side. Then, select (click on the first, hold down the Shift key, and click on the last) all the entries and right-click to delete them all. Click the Save button to save the file. Now go to Sim Wants and Fears and do the same thing.

For Downtown and the OFB neighborhood it's exactly the same as for Universities. The location of the template is C:\Program Files\EA GAMES\The Sims 2 Nightlife\TSData\Res\NeighborhoodTemplate.

If you want to keep some of the sims that come with the Universities or Downtown, the process is slightly more complicated. First, open the U00#_Neighborhood (for the Unis) or D001_Neighborhood (Downtown). Click on Sim Descriptions. You will need to locate each sim you want to keep, and write down that sim's file number. For example, D001_User00000 is Jon Smith Tricou. To make things simple, you will want to keep all the sims who know each other. Otherwise you will have to edit memories as well, and that's a whole other level of complexity.

I can make this even easier by telling you which files to keep.

In the Downtown, you should keep the following: # 00000, 00019, 00044, 00051, 00054, 00055, 00056, 00060, and 00061. This gives you the whole Tricou family and Rainelle Neengia (a total of 9 files... Rainelle is # 000019 if you want to delete her). In Uni #1 (U001), to keep all the Maxis pre-made sims and the sims they know, you should keep: # 00000 through 00014 (this gives you 15 files for this Uni). That was easy, they're all in sequence. For U002, keep # 00001 through 00016 (17 files left in this Uni). Easy again. For U003, keep # 00000, 00004 through 00009, and 000034 through 000038 (12 files left in this Uni). After deleting all the rest, DO follow the previous instructions for how to open the file in SimPE and delete the unknowns, but DO NOT follow the instructions for Sims Wants/Fears, and Relations.

Now let's take care of some dangling Sim Wants/Fears, and Relations.
Open the U00#_Neighborhood file and choose Sim Relations on the left-hand side. Delete all the ones that have Unknown in them, like Bella Goth toward Unknown or Unknown toward Cassandra Goth.
Next choose Sim Descriptions on the left-hand side. Do you see the sims' names? Get an index card and pen. Do you see a heading called INSTANCE after the sims' names? Each sim has its own instance number. Write down these numbers on your index card, just the last part is fine (like 3, 4, 5, 29, 1E, 2D etc). Now choose Sim Wants and Fears from the left-hand side. You don't get sims' names here, so you'll be relying on the instance number. Delete all entries except the ones with the instance numbers you wrote down.

Okay, so we have just learned how to edit the Universities and the Downtown, to empty them of unwanted/ugly/junky characters that we hate having dumped into our game each time we attach a Uni or Downtown to one of our neighborhoods. If this stuff made sense to you so far, you are ready to mess with Pleasantview, Strangetown, and Veronaville.

There are two reasons you might want to edit these neighborhoods.

#1: To have a less ugly-townie-infested version of the neighborhoods, but still keep all the pre-made Maxis families. Also useful if you want to correct all the Maxis mistakes once and for all. People who restart the neighborhoods often probably know what I mean. :)

#2: To create a new template for custom neighborhoods. The sims you add to this template will be added to every custom neighborhood you create. They'll keep most of their attributes like looks, clothing, name, personality, interests, aspiration. I haven't really checked what they don't keep, but I assume it might be lifetime wants, careers, and turn on/offs.

Let's begin with #1.

Let the game generate a new set of neighborhoods by removing entire The Sims 2 folder from C:\Documents and Settings\Owner\My Documents\EA Games. I will assume you know how this process works. If that folder is removed, the game regenerated the three default Maxis neighborhoods the next time you run the game.

Once that has been done, edit them, play them, mess with them in SimPE, whatever. You should probably correct all the problems, like DNA mistakes (see this thread), surname inconsistency (Singles?!), missing or incorrect family ties, messed up memories, and so on. The only thing you CAN'T do is attach a Uni or Downtown.

When the neighborhoods are to your liking, open C:\Program Files\EA GAMES\The Sims 2\TSData\Res\UserData\Neighborhoods, which is the location of Pleasantview, Strangetown, and Veronaville, and delete the N001, N002, N003 folders and the NeighborhoodManager file.

Next, go to C:\Documents and Settings\Owner\My Documents\EA Games\The Sims 2\Neighborhoods, grab the N001, N002, N003 folders and the NeighborhoodManager file, and move them to C:\Program Files\EA GAMES\The Sims 2\TSData\Res\UserData\Neighborhoods.

Basically you are just swapping the unedited templates with your edited neighborhoods.

Here are the character numbers for the neighborhoods. Be careful when doing this, since there are so many files and many of them are not in any kind of sequence. Also remember that this includes all the dead sims, all the Maxis pre-made playables, and any townies and NPCs that they know. For example, Dustin Broke knows a burglar, so the burglar is included.

Pleasantview (N001)
NOTE: This is a version that has about ten townies. I think the ones included are Komei, Benjamin, Jan, Meadow, Brandi... ugh, I can't recall the rest.
00000 through 00072, 00081, 00086, 00090, 00101, 00126, 00127, 00137, 00140, 00142, 00147, 00151, 00155 through 00157, 00162 through 00170.
A total of 95 files.

Strangetown (N002)
00001, 00003 through 00018, 00026, 00035, 00036, 00041, 00046, 00058 through 00060, 00062, 00064 through 00072, 00076, 00077, 00079 through 00085, 00089, 00109, 00132 through 00134, 00152 through 00155, 00170 through 00177, 00181, 00182, 00183, 00185 through 00189, 00191 through 00212.
A total of 91 files.

Veronaville (N003)
00000 through 00004, 00009 through 00020, 00022, 00023, 00025 through 00032, 00034, 00035, 00111, 00112, 00116 through 00119, 00122, 00125 through 00129, 00132 through 00134, 00139, 00141 through 00146, 00152, 00154, 00155, 00158 through 00166, 00169 through 00199.
A total of 93 files.

After deleting any character files, you'll need to take care of the dangling Sim Relations, and Wants and Fears.

That covers that. Now for #2. This is the one where you want a new template for custom neighborhoods.

Use the same procedure as for #1. You want to be able to play in Pleasantview. Don't delete the other two neighborhoods since that may screw up the NeighborhoodManager file. Just don't touch them, since you don't need them. Also remember that you cannot attach a Uni or Downtown.

Go into Pleasantview and use the code DeleteAllCharacters to empty the neighborhood of all sims. Exit the game.

Open the N001_Neighborhood file in SimPE. Follow the instructions for removing the dangling Sim Wants/Fears, Relations, and Unknowns in the Sim Descriptions.

Go back into the game. Create your own townies and NPCs. I assume anyone who is attempting any of this already knows how to do that. BIG NOTE: You cannot leave any sims as playable characters. They MUST be in a townie or NPC family in order for the game to know that they should be copied over to a custom neighborhood. So you can't just create a family of sims and leave them on an empty lot or in the bin. I recommend using Inge Jones' teleporter PLUS shrub, which you can get from MATY's Peasantry forum.

Once you are done making all the sims, open C:\Program Files\EA GAMES\The Sims 2\TSData\Res\UserData\Neighborhoods, which is the location of Pleasantview, Strangetown, and Veronaville, and delete the N001 folder and the NeighborhoodManager file. Don't worry about the other stuff... you didn't edit it so you don't need to touch it.

Next, go to C:\Documents and Settings\Owner\My Documents\EA Games\The Sims 2\Neighborhoods, grab the N001 folder and the NeighborhoodManager file, and move them to C:\Program Files\EA GAMES\The Sims 2\TSData\Res\UserData\Neighborhoods

And... that's all, folks.

Again, NOT for people who either don't think they understand this process, or for those who would be overly upset at having to reinstall the whole game. And DEFINITELY NOT FOR PEOPLE WHO CAN'T CREATE PROPER BACKUPS. I had to use my backups at least four times while doing all my editing. Of course, I was just discovering this process as I went along, so it's not surprising I screwed up tons of times, but I wouldn't be surprised if you needed to start over once or twice too, especially when editing the Neigborhood files in SimPE to delete unknown sims.

Last note: If you are leaving some sims in a Maxis neighborhood, it's a good idea to get this plugin and have it check memories.