Gma_tools.exe -

Select "Extract" and choose your file. A new folder will be created containing the addon's source files. :

: Easily unpack Garry's Mod Addon (.gma) files to access their underlying assets like models, textures, and sounds. gma_tools.exe

: A multi-purpose tool that can pack, unpack, and publish various Source Engine assets. Select "Extract" and choose your file