Taking an MBA in Portugal is a hard job. But should you wish to do really do it, get ready, because it's a lot of trouble just to make an application (it's sort of a preview of what will follow...). What I suggest is that you look at the offer, in the first place, not only in terms of the curricula, but also of schedule, because if you work full-time, this will surely affect your decision.

Then, you should get information on the tests

you will have to do in order that your application be accepted. You  usually have to do a test that will evaluate your analytical, mathematical and synthetical skills, GMAT (in English). Additionally, in case you are not a native English speaker, you must make a test to assess your interpretation and speaking abilities of the English Language (either TOEFL or IELTS)because some courses are taught in English. The next step is to decide which Business School(s)deserve your application (and money...). Here are a few:

Oh! and don't forget that each of these steps(that is, each step and application) requires a payment. Of course, if you are lucky enough to have your company "contributing", that will not be a problem...

After making the tests and completing the application processes, all you have to do is wait for the results, which shall be sent to the Business School(s) indicated as you enroll for the tests. Should you manage to enter the MBA program:

1- Get ready to suffer (you will!);
2- Realize that there will be no socializing for 2 years;
3- You will face challenges that will prepare you for those you will face in your professional life;
4- You will, surely, make friends for life;
5- Your CV will never be the same again.

The best description of what an MBA is was probably the one made by a friend of mine, which attended the course one year before (finished in July 1997):

If you still wish to go along with this, I will be glad to be of assistance. Just contact me!