How does one make a model their player model that ISN'T in the models section under options?

Details: I play HL2RP a lot, and I have a few really neat combine skins downloaded from that, specifically the EpU and the MeD units. The skins are saved into gmod, when I go to browse I can find them. BUT; they aren’t in me models.
P.S.: The server I am trying to do this on has PAC editor and wire, in case that matters. Also, don’t just say “Just throw it in PAC hurrr” without telling me what to do because I would like it if my legs and stuff moved with me.

Thanks for any answers in advance,
Glyptodon :worship:

To be honest, I can’t understand any of questions you wrote, also have no idea what you are asking for.
Also don’t sign your posts, it looks retarded.

You have to use the bonemerge option in pac