The PC files are a separate download from Android and only work with the Steam version of the game. The steps are the same for every mod.
SFA_Data\StreamingAssets. It’s usually C:\Program Files (x86)\Steam\steamapps\common\Shadow Fight Arena\SFA_Data\StreamingAssets. Replace the files when Windows asks.%USERPROFILE%\AppData\LocalLow\Nekki\Shadow Fight Arena\gamedata\Resources\Bundles and press Enter. Keep the exact file names (no extension) and replace the files.Undo: close the game and put the backups back. Steam can also restore the StreamingAssets files: right-click the game > Properties > Installed Files > Verify integrity of game files. That doesn’t cover the Bundles folder, so keep backups of those files.
Each zip’s README.txt has the same steps and lists which files go where.