I've been attempting to do this myself but have given up now.
I want to have IQ from Rainbow Six: Siege as a player model for CS:GO, but cannot wrap my head around how to convert the model and skeleton to work for CS:GO from a Garry's Mod model.
Thus, I find myself requesting if someone can possibly do it in my stead? I'd be forever grateful, etc, etc. :p
Possibly helping me do it myself would also be nice, though I have a feeling my knowledge in rigging is too weak to do much more.