I am working on creating a rigged character that is fully customizable, right down to the lengths of various body parts like the arms, legs, and torso. I found a tutorial for stretching the joints of a proxy rig in the manner that I want, which can be watched at the following URL.
The problem is that the rig I'm creating is already skinned. What do I need to do to make my joints stretchable in a rig that is fully skinned?