Steps to changing Clutch (BUrb), must you remove the muffler?

[OverRunWithSons]

My husband has not decided whether to NOT remove the muffler when changing the clutch, requiring him to use a Jack and hold the Transmission up while sliding it back along with the motor (sounds very dangerous to me, worried it may fall on him), or taking the entire muffler off -which gets into those difficult bolts that can break off into the engine and cause more problems to solve. He has already removed the transfer case. Please tell me which method is preffered, or you generally do -when changing a clutch? It is a '88 Sburban.