It looks doable, and I already have the Sonnax wave plate repair kit.

 

Mine was replaced under extended warranty by GM.

It is my understanding that this involves disassembly of the majority of the innards to get to the plate to replace. Additionally, the shop that worked on mine put the tranny mount on incorrectly. To do so, they would have had to disassemble it to pull the transmission.

I will also add that I have never knowingly stood next to anyone who has performed transmission work let alone done so myself.