It's basically easy, you can see a lot of AAA=BBB in the files I linked your to. AAA is the tag the game itself uses, and BBB the text to be translated.
Of course in the section [LANGUAGE] you will see NAME=English, and TRANSLATOR=Jeroen P. Broks, well, there you can put in the Portuguese word for Portuguese as NAME and the name under with you wish to be credited under TRANSLATOR. The best way to go is to copy the contents of the upper link in my previous post into your favorite plain text editor (even Windows Notepad will do) and you can just translate everything right of every = mark.
Oh yeah, everything between [ and ] is for the game to find the sections by, but should not be modified.
I already explained how to use accent mark. If you type "Je suis fatig|'e" in the file the game will display that is "Je suis fatigé" (mean "I am tired" in French).
I made the system as easy as possible.
(If you wonder about the game itself: https://phantasar-productions.itch.io/house-of-cards).