Addons
For GMOD users, you will also need the Extended Spawnmenu addon to load any legacy addons.
Note: For all Pokemon addons aside from SV addons, the Shared Textures pack is required. The GMOD version of the Burnout Paradise pack requires the Shared Vehicle Assets pack.
To install GMOD addons, download and unzip the addon into the addons folder into "GarrysMod\garrysmod\addons" directory.
The addons will show under the "Addons - Legacy" folder if the Extended Spawnmenu addon has been subscribed.
To install SFM addons, download and unzip the addon into "steamapps\common\SourceFilmmaker\game\usermod" directory.