How Can I Edit A Ragdoll Template?

So I finally got to downloading the newest PonyPack for Gmod, and I found cool templates in there I’d like to use… but how do I use them? I want to make mine and my girlfriend’s OCs using the templates but I’m not sure how…
Also, is it possible to put a horn onto a pegasus pony? My OC is a pegacorn, but if that isn’t possible, I can stick with her being a pegasus.