Where to find a tutorial for importing models and textures from Steam games to Gmod.

Is there a tutorial for doing this that does NOT require me to download a base that imports for me?
I am willing to take the long route in order to skip downloads.

What?
Are you using a pirated version of gmod?
Othervise it does that automaticaly.

Uhh… Most Source games are supported already. You obviously have to own them, though.

For unsupported Source games use gm_mount2.