Tips on removing stock exhaust

[samuel642000]

On my DD I'm trying to remove the cat back without cutting it. The problem is at the connection the Ubolt clamp, for lack of a better word, crimped the two pieces of pipe together.

I've tried heat(propane torch) and a BFH, is this about the only way to get it off or are there some protips that would help me out?

Was thinking about a punch to beat in there and space them out.

Just curious if anyone has anything for me to try, minus a cutting utensil.