The games files should be un-encrypted, you should be able to open the Game.rvproj2 file included with the installation and edit it freely.
You are more than welcome to translate the game into Portuguese! Although I imagine Ekoi's dialogue might be rather tricky as he speaks with quite a verbose vocabulary with lots of long antiquated words, I'm not sure what the equivalent words in Portuguese would be for some of them.
Let me know if there's anything you need.