After the edges were deburred, we slipped the C-notch insert over the framerails by gently tapping the insert with a hammer and a block of wood. The left framerail’s lower edge had a rolled lip that wouldn’t let the insert slide on all the way, so we had to trim a little more off that edge. Once that was done, the insert fit right. Eight 1/2-inch holes were then drilled through the frame--six through the side and two through the bottom--to bolt on the insert. Once the holes were drilled, the supplied bolts and Nylok nuts were installed. With the C-notches secured, we installed the new urethane bumpstops.