To access Kerio's rule list, make sure Kerio is running and right-click it's little blue shield icon at the bottom right. Select Administration from the menu list, then click the Advanced button near the middle of the Administration window. You will be presented with the rule list.

To scroll around, DO NOT use the square arrow keys at the far right: those are for moving rules around within the list. Use the normal Windows-ish arrow keys and slider, a little closer to the middle on the right.

To move a rule within the list, click it once to select it and now use the square arrow keys at far right to move it.

To disable a rule, click the box next to it to uncheck it. Don't forget to re-enable it if you want its protection later on!

To edit a rule, simply click the rule to highlight it, and click the Edit button.

To insert a rule above the currently highlighted position, click Insert

To add a rule, click Add. It does not matter if anything is highlighted; added rules are always placed at the very bottom.

To delete a rule, select it and hit Delete.

To install a new ruleset, right-click Kerio's icon, Select Administration, (DO NOT select Advanced) and click the Miscellaneous tab along the top.

Remember: the order of rules in the rule list is extremely important!
Also: in order for changes to take effect, you must hit the Apply button before exiting the rule list screen.