Hybrid hatch - TTRx7

Hey fellas, I have a '92 hatchback and I want to install my 3 piece mid wing......The middle piece I think I got, but my question is for the two outside pieces......When I took out the interior in the back it seems as if I have to cut some metal to get to the spot to mount the outside pieces for the wing ?!? This can't be right......Any suggestions would help, Thanks.