I think i honestly just dont produce enough force to get them lose. Im going to try again with a breaker bar and see what happens before i resort to cutting it off.
spray a good amount of WD-40 or some sort of oil in the clamp, loosen it all the way, get a screw driver to pry in between the clamp and the pipe and see if that works
if you have a 5lb hand sledge, combined w/ a breaker bar, it should come right off. now, if it doesnt, cut the pipe work off just in front of that factory clamp and you can get another exhaust clamp from VatoZone.
fugg wd-40. You need some PB Blaster Its a penetrating oil that will actually work through the rust, WD-40 is just a water deterrence.... its not even that great of a lubricant...
loosen the clamp and just tie your muffler to a palm tree and drive forward to pull it undone! what could go wrong?