Engine/transmission swap

Howdy all. Asking for a friend. He has a 2011 Synergy Green RS with a V6 and the Auto transmission. Recently we discovered he has a knock in the engine and we were just shooting around the idea of swapping it for the LS3 V8 and the M6 trans. We enjoy the work and experience of doing it ourselves and we both have mechanics in the family that would help us swap it but how involved is it to go from the V6 to the V8 and the auto to the manual. Before we jump the gun, we want to know JUST how much we are going to have to change and just price it out.

I’ve read about needing the engine wire harness and the dash harness which makes sense but that’s all I’ve seen. Are we also going to have to change all the modules and computers inside? New engine mount points? Adding the clutch petal is obvious but how involved? Would it even be worth entertaining the idea. Thanks y’all!