Showing the cut section. As you can see, I left a little extra on the donor piece for 2 reasons: You can always cut more off. In order to match the roll of the rear of the fender, we tacked the rear face in place, then slipped the side skirts of the donor section into the stock fender. This allowed us to bend/shape the fender to match the natural curve, and also gave us a solid line to mark and cut the spliced section.