Get a 11/4 inch hole saw and cut around the exiting exhaust outlet. Once this is done jam a tapered object inside the exhaust pipe and start wiggleing, twisting, cussin' and dancing and eventually the perforated tube will break off. This tube is only approx 6-7 inches long and is spot welded to a raised ring inside the OEM exhaust.
This tube is NOT the spark arrester. The spark arrester is further inside. Now that the tube is out and you have removed all of the spot welded pieces. (I sharpened a large screw driver and used it for a chisel) There is approx 3/8 inch of packing, the length of the tupe that can now be removed. I started the engine and blew it all over the floor.
Get a piece if 11/2 inch exaust pipe and cut one end at a slight angle so that it points down and out to the right side of your bike. (about 2 inches long) Angle cut against the muffler. Now weld the the pipe to your muffler.
This will relieve some back pressure and will create a deeper sound (Slighty, not like a Harley) I did mine and I'm happy as a clam. This whole proceedure can be done without removing the muffler from the bike. Just make sure when you tack weld the exhaust end on you cover the bike plastics and other areas with wet towels. This should also kill the tweety bird, dead.
I would enclose pix of how this is done but I'm too dumb to know how to do that.