Morphing a player by setting a new character?

Player.Character is a reference to the character model in workspace. Since this is true, then it should be possible to set the reference to a new model. However, how would one go about this so the parts and limbs don't break.

Yes, I've used :MakeJoints().

I would like to know the way for R6 rigs and R15 rigs. Is there a part hierarchy required to follow in order for the character to work?

I've seen it done before but I don't have access to the script. Does anyone know?

I would love to know this method as it's much more efficient that making separate code blocks for individual morphs.