I used a little portable propane torch to heat the coating then used a paint scraper. It is not a five minute deal, and you may want some lung protection because if it is the same stuff my 48 had under it, it is a tar like material. Once heated the outer layer will come off with some elbow grease, you may be able to follow up later with an oven cleaner or something to get the hard to scrape stuff off. Oven Cleaner from the start wouldn't penetrate the 1/8 inch or so of undercoating material on my frame and undercarriage.

Brian