If he opens it back up drill 2 holes on each side, all the way though the pipe. I used a step bit, so I could only make the top of the hole full size. Both of the holes on the top of the pipe are 3/4 of an inch. The bottom holes are smaller. I put it back on the car with these size holes. I felt it needed to be louder. So I took the muffler back off and used a chisel to connect the holes. Basically I went through the pipes on the side of the muffler, placed a chisel in the hole closer to the end and hit it with a hammer until the holes connected.