One of the most common (and not-too-difficult) custom car mods. I believe most people use the severed piece of the hood as the new filler piece on the body. Then, it's just a matter of making templates for the metal strips that will finish off the raw edges. If it was me, I'd try to make the filler piece out of a piece of "L" channel so there would be a finished return edge. You could use a shrinker/stretcher to get the curvature right.