Without actually seeing it, hard to offer advice, only guesses. I have replaced the rings myself before. Been awhile. I don't know if maybe you gotta loosen and twist the muffler a bit so the bracket is in a slightly higher position. It has really been a few years since I did it. Seems I had to use a floor jack under the muffler to sort of 'force' it to go a little higher so I could get the darn thing hooked. (Hmmm. Let me think some more.) (If you do that, by the way, careful you don't mess up the muffler with the jack.) Was the old ring 'super-stretched' out? I sort of recall that I had to remove some of the other rings so I could "tilt" the pipe so I could hook over that one ring, then put the pipe back on the rings I removed. Might want to replace the other rings also at that time, if need be. Also might just going to take some more stretching and cussing! Good luck.