"Headhacking" tutorial?

So I heard alot of talk about “hacking” the heads from human (obviously) models and putting that head onto a completely different model, say I want to change the Team Fortress 2 Medic’s head into a HL2 citizen’s head.

:google: came up with nothing so I’m asking here.

Is there a full tutorial anywhere for a guy who has 0% experience with modelling programs that would be easy to follow and stuff?



Many thanks! :smile: