Brazing or MiG welding a patch on is a viable option if you can find someone willing to take on the job. Due to the location of the resonator, be prepared to have to remove it before a welder will touch it, though.
Thanks, is this a chore for a welder?
Also, I have asked if removing the muffler is as straight forward as it looks. No particular sequence of pipe disconnect or frame disconnect etc, etc.
We are talking novice here.
It's a chore in that it lies underneath a vehicle with low ground clearance and in close proximity to the rear tire. The process of welding or brazing creates a lot of heat and sparks, so most welders would much rather have the component removed and on their bench instead of lying on their back on the floor to access it. Best bet is to take the bike to a couple of welding shops and see what they say.
Ok, now we've reached the end of my memory files... it's been seven years since I put Roadhouse mufflers on my Drifter and honestly cannot remember what the procedure was to remove the stock exhaust system. You really need to get in touch with the VROC folk for any further help with this.