1986 500 SL. Trying to uncouple cat and muffler.What is the best way to uncouple the various exhaust joints that have the bolts/couple flanges/seal rings. I have the bolts and flanges loose, but is it going to take heat to get them uncoupled? I have never dealt with the seal ring before. I think I could pull and twist on joints forever and the would never come uncopled.

Thnaks