Rigging a model

Mariokart’s tutorial is to difficult for me to understand, so could anyone dumb down on how to rig a model? You see I am doing a headhack, but I’m using two different ragdoll bases and would like to rig and overlay one over the other. Could anyone please just try to dumb down this as easy as possible? Thanks in advance.

Attach a the head object to the body, and add all the bones given