"P" clamp is easiest way to do it in my opinion. I think it takes a 3/4", the bolt to go in the nut on muffler is a 1/4x20 about maybe 3/8 long. As far as knocking the CAT material out, you can buttttt the videos I saw Harley guys posted its a PIA. Certainly not worth it when you can pick up non-cat mufflers cheap enough.