Did it to my 2003 1100 Custom. It was simple. Once you saw through, just grab the end of the pipe with a pair of pliers and rock it around in circles. Comes right out. Just do yourself a favor and buy a 'good' hole saw. I tried it with my cheap China one and ended up running to the hardware store in the middle of the project because the saw lost all of it's teeth. The good one was a Irwin bi-metal. The sound is pretty cool and it will work until I save up enough for slip-ons.
I did it to my 2009.It was very hard to get the pipe out because it is not straight it is curved.take the slip ons off to do it.I will say it was well worth the time because it sound very nice.I also did the ram air mod and together my power and fuel economy have improved greatly.