Holy crap Source SDK is hard to deal with. Oh well.

v1 download: https://www.yoshiartists.com/uploads/misc/yoshiegg.zip

Extract the folders you see such as materials/ and models/ into steamapps/common/GarrysMod/garrysmod/. There should already be the folders in there, just have it add the content.

They will spawn as white, but color them with the Color tool and you'll see the spots show up