Well, the quickest, easiest and cheapest method is to buy a new hood, so I'd recommend that route.
However, if you want to make a mold and a new part, the right way would be to...
Chop the hood, use foam and bondo to get the shape you want out of the hood. Sand the bondo down with 220 or maybe even finer to get a fine finish that you can still paint. Spray it with tooling Gel Coat or maybe a paint to get a paint quality finish. Wax the part with a quality wax, then spray it with PVA mold release, then spray it with tooling gelcoat. Next layup resin and glass, you should use epoxy as poly can shrink. I like to work with Biax glass. You should make the mold twice as thick as the part but do not layup more than 1/4" of glass at a time to prevent heat warp. Pop off the mold, then repeat the prep for the part (wax, PVA, Gelcoat, Glass). Remove part. Prep, paint. How thick the part should be... I don't know. Maybe 3-4 layers of 17oz biax? I'm not sure how thick it should be.
It's a very involved process. It's also a hard thing to do with limited glass experience. Last mold I attempted to make came out only okish, and the part I pulled I was not pleased with. The problem with the hood is the hood has those 90* angles with only a slight curve to the edges, which makes it challenging to copy for people like us (with limited experience).
