The piece between the cans, I just carefully moved in between them. You could put a few layers of masking tape on the can surfaces while u r installing. I don't like the gap in the tail light and the plastic piece(stock set up does this too), so I bent the hanging piece between the cans to raise it up a little. The mid-pipe and two cans you will need to jockey around a little bit to get perfect alignment. The circle with the three holes I don't think it was used. If u send a picture it may jog the memory.