I had the exhaust tips installed in 20 minutes - no need to remove anything. Painful to watch but the shop used a saw-zaw and cut the pipe leaving an inch sticking out from the base of the muffler. He put the tips on and tack welded in place, checked for alignment and then welded in place.

Depending on your taste, I had the shop cut the tips by 2 inches so they would tuck under the bumper.