Screwed up shotgun

Hey my original shotgun model and everything about it accidentally got replaced by an addon that i downloaded. so now anything that has to do with a shotgun is showing this crappy addon model. npc’s wont shoot with it and i hate it. Is there a way i can bring back the original model WITHOUT reinstalling the game?

just delete the custom shotgun files.

delete shotgun files in addons folder

It has replaced the original model in the gmod files. im sorry i called it a addon i meant it was a downloaded file. This particular one was not an addon. it was pasted directly into the gmod directory.