first you need to download the files for the language you want to install. we have a list of official translations that are not on steam we managed to find here: https://www.speedrun.com/bo1/resources

remember to create a backup of any files you change/delete

once you download it, there should be a folder called main and a folder with the name of the language you are installing.

inside your game files, look for the ''main'' folder and delete every file with the name ''localized_[current language]_iw00-14/15'' inside of it.

inside the ''main'' folder from the download, find and drag every ''localized_[new language]_iw00-14/15'' file to the ''main'' folder from your game.

inside your game files, look for the ''zone'' folder and delete the folder with the name of the current language inside of it.

drag the folder with the name of the new language you downloaded inside the ''zone'' folder inside your game files.

inside your game files, look for the ''localization'' .txt. rewrite the first line to the name of the new language and save it (if the file you downloaded gave you a ''localized'' .txt, you can just replace both).

start the game and have fun with the new language.

note: if you find a ''video'' folder inside your download, you need to drag it to the ''main'' folder inside your game files.