I have just done this mod on Louise's (mrsmonster) class B bike. It is easy enough to do but cutting off that lastt little bit of pipe took a while and lots of dremmel grinding discs. The bike sounds like a Ducati now but probably now power difference.
I did it working from inside the end of the can without taking the tube off which saved a lot of grinding and no welding back together.
I also cut a small V out of the inlet pipe bent it up and had it welded so the exhaust is more upswept.
http://www.ducatisuite.com/mufflers.html Hope this helps.
