Here's lots of tips from other Hometalkers Jeff that should be of help :)
Baking soda and vinegar or Brillo Pads, or Oven Cleaner from the store!
Before you do anything read your owner's manual (you can download one with Make and Model) so you don't harm it or void any warranties.
Hello -this link should be helpful.
The steamers to clean with I really like--no chemical. And from this daunting chore we learn to take precautions to not let it get 'that messy ever again'.😨 Barriers underneath to catch drips, covers-even foil placed on top to prevent splatters, etc