I removed the fiberglass lining from the inside. Split it down the side and stuck the glass pack in and welded them up. What I wish I would have done is: Stick the glass pack into the outside piece of metal and weld the side up. Center it in there were I want it and before welding on the ends I wish I had welded the front side of the new glass pack all the way around to the outside of the original muffler casing or metal. After having the mufflers on the bike awhile I can hear the exhaust blowing past the outside of the glasspack. Not that big of a deal, but my ears are not the best and it bugs me that I can hear that noise. It would just sound much better if the exhaust did not leak past the outside of the glasspack muffler. Most people do not notice I am sure, but I hear it. I now wish I would have taken a few more minutes and welded it up better. One day I may reweld it. Good luck. The other thing is I took the left side muffler off so all the exhaust now goes out the right side muffler.
Buckeye, Arizona(USA) 2011 Victory Cross Roads, Black police bag guards, black engine guards, black handle bars, Triumph Tiger mirrors, Triumph hand grips, set speedo/tach back 5" , adjustable timing wheel, Lloyzz Fuel Programmer III & air filter. Modified exhaust, made stock into 2 into 1. MRA windshield, Rotated front fender forward,relocated ignition switch, Bad Ace Fuel Tank Risers, Fat front tire.