This catalytic converter shield was difficult to install. The four pressed in nuts require large holes (perhaps 7/16") for the pressed-in pieces. The directions state the you can install these without the need for the special tool with the included instructions. The needed instructions were not included. The manufacturer provided the instructions upon request.I decided to punch the center of the needed holes before using a small pilot drill. Whether I didn't have the truck high enough off the ground to get a good swing at the punch, or whether the steel is extremely hard, or whether I am too old or weak to swing the hammer well, I do not know. But I know that I failed at making a depression in the steel to keep my drill centered. So I cheated. I drilled holes for the correct metric tap, tapped the holes for the tamper proof bolts, and installed the tamper proof bolts.Maybe I did a terrible thing, but my shield is holding on fine, and my cross members have more steel left than they would if I had followed the directions.