A while back I attempted to chop my stock exhaust but was stymied when I could not budge the outer aluminum sleeves, so I resorted to a less radical procedure involving only drilling a bunch of holes in the rear wall to open up that last chamber. The improvement in sound was great, but I was still left with stock cans that protruded way out the back of the bike after chopping the tail.
Thanks to some encouragement from caffeinejunkee, I finally went back and did it the right way. I gambled that if I chopped the cans with the sleeves in place that I'd be able to budge them easier after the chop and I was right. The simplified procedure: remove cans from bike, position in chop saw (I took 3.5" inches off), remove sleeves from the cut-off part and cut welds to remove end caps, slide sleeves down and debur/clean chopped ends, rivet end caps back on. The whole job took about 2 hours with removing the end-cap welds the toughest step. I learned from the first one that the easy way to cut the welds is to not attempt to grind through the weld itself - just use the cut-off wheel (I used a 3" wheel attached to a regular 3/8" drill) to cut through the sheet metal of the end cap just above the weld. Piece of cake and plenty of end cap flange left for refastening.
I'm considering painting the cans with a high-temp black wrinkle (like used on some valve covers, etc.). Opinions?
Pics and video:
Before:
http://www.flickr.com/photos/sejman/3503253014/#in/set-72157607797890204/After:
http://www.flickr.com/photos/sejman/5361550662/#in/set-72157607797890204/http://www.flickr.com/photos/sejman/5360941471/#in/set-72157607797890204/Video/Sound: