Guide:Unpacking and Converting Files
https://bg3.wiki/wiki/Guide:Unpacking_and_Converting_Files

Norbyte/lslib (Tool for unpacking and repacking .pak files
https://github.com/Norbyte/lslib/releases

Modding BG3 Tutorial - New Armour From Existing Assets
https://www.nexusmods.com/baldursgate3/mods/1508