HELP!! Big grease problem.
Get a wallpaper scraper. Or a hammer and chisel. Or one of the large handled grill scrapers with replaceable blades. If you can find a large enough container. leave the filter machine (not the electric part) in the container filled with hot water and fryer cleaner overnight. Oven cleaner will also work on both. Several applications may be needed. A professional steamer may help. They have them for rent or you can buy one and have it on hand for about $750. Keep working at it.