Wash it. Dish soap should do it. If not, try vinegar. Get your crew to be more tidy. Wipe down daily after the dishes are done.
I use fantasik spray to remove grease and buildup on outside of microwave then dry it off and use windex to shine it up
How to clean plastic 'window' on appliances? - Houzz
Mr Clean majic eraser....that is all
just use white vinegar
I agree: White Vinegar.
Nice thing about Vinegar. It's already bad wine, so it don't go bad worst.