This past tue i decided to do somthn to my pipes but wasnt sure what to do. I first took a 1/2 inch dril bit nd put 5 holes around the lil pipe in the middle of the pipe. Didnt really do anything and I was p/o. I then called a friend that has more tools and he brought over a hole saw that just fits in the lil pipe. The hole saw had an 1ft long ext. on it. We took the muffler off the bike and put them in a vise. There is a 3 plates and converter in that big pipe. We drilled from both ends and removed all that was lose. The pipes look just like glass packs now. We put it all back together and now have 250 miles on it and love the sound. Very lil backfire and no performance lost. Hope this helps any body wantin to do this cause I love it and my friends do to.