yeah
measure2 inch away from the pipe hanger, this is where you are going to cut. Make sure you measure in the direction that will preserve the hanger.
tape a piece of masking tape around the circumference of the pipe. This will help you keep a straight cut.
My advice is to use a grinding wheel or metal cutting wheel and cut to the left of the tape flush with the edge of the tape. Don't worry about the smoldering tape, it will come off.
You are going to cut about a 1/2 inch into the metal. Once you get through the top layer to the muffler baffle, the baffle will literally pull right out.
(this can be messy)
use the same grinder and grind down the flange around the muffler cap so that you will be able to separate the cap from the stainless steal can and use the same cap to slip back into the can.
you will need to modify the baffle to make it shorter so it too will now fit into the shortend can. try to preserve as much insulation as possible. You will need to tack weld or rivet the cap in place on the underside out of sight, the back pressure will force the cap out once the can is really warm.
I suggest that you use a grinder and tack welder, the stainless steel they use for this can is hard as hell. I was very impressed. if you use a hack saw you will have a 24 hour project on your hands, with the right tools it's only a 3 hour project.
I don't believe I am forgetting anything, but look at the other threads. But use power tools, it's worth it.
PS you do get back pressure popping with this mod. Its fun if you live in the city. when it pops people duck!