Push it off
I just removed my muffler, and was able to push it off using a short hydralic jack. Just put the jack between the resonator and the muffler. I used two small wood blocks to help prevent denting the items. With the clamps all off, and the hangers free, the muffler pushed off with very little work. Yes the pipes were dented from the original clamp, but it was not a problem.
Hope this helps. Greg L