To download and install the for The Witcher 3: Wild Hunt
This is the method implied by your keyword search. It is better because it works even if GOG Galaxy is buggy. Portuguese (Brazil) language pack To download and install
Click the button (three dots or gear icon) next to the Play button. Navigate to Manage installation > Configure . Portuguese (Brazil) language pack To download and install
Find the dropdown menu and select Portuguese (Brazilian) . Portuguese (Brazil) language pack To download and install
Antes de baixar, é importante entender que a versão GOG (Good Old Games) é a versão "Completa" (GOTY - Game of the Year Edition) na maioria dos casos hoje em dia.