Help with porting a MMD model to Gmod?

Hey, I created an account to ask this, as I have been really stuck.

I ported a MMD Model to Blender with no difficulty at all. I’m really stuck on the rigging, as I’m kinda new to the whole ValveBiped thing. Ideally, I would make it just a ragdoll, but a playermodel is optional, too.

Could someone tell me/link me as to how to do this? Thanks!