I wish I had found a magic potion that would melt the grease off and provide a surface ready for painting ... But what works best for me is Elbow Grease -- a lot of scraping with a paint scraper/old gasket scraper, followed by liberal applications of Dollar Store oven cleaner, more scraping, more oven cleaner, more scraping, more oven cleaner ... then pressure washer with Dawn detergent ... wire brush ... once more oven cleaner ... wipe down with acetone, or sand blast.
If there's an easy way to degrease, I'd like to know what it is, too
