Okay, so I've installed a alicorn twilight (but it has normal pegasus wings) and Granny Smith, Pinkamena, and Cheerilee, but I tried to install a female pony overhaul the same way as I did with them and that is the only one that hasn't installed successfully. *Note, I'm putting them in my steamapps / common / garry'smod / garry'smod / addons / folder with the Legacy spawnmenu *
EDIT - Turns out materails/models were interrupted during the proccess, all done!