Choosing your model-Please help

I downloaded a sweet russian GP-5 gas mask man. How can I make him as MY player model? I

If he doesn’t appear in the player model list, look for the model name and then put THIS in the console…
cl_playermodel *
Example: cl_playermodel alyx
But, it HAS to be a player model, not a ragdoll, or it will not work.

Well I it’s not a model. but like i added an NPC. It’s on the NPC under “Soviet Quarantine” But when i do “cl_playermodel Soviet Quarantine” My player does not change.