put the single GSC file in a folder called "maps" and then a put another folder inside the maps folder and call it "mp" and then put another folder inside that folder called "gametypes" if the GSC is _clientids. if it's a _development_dvars then it's just maps/mp. anyways go to GSC studio, connect and attach, go to editor and click "Inject compiled script file" and then find that maps folder and then you should be able to inject that single file