Microwave a bowl with 1 cup of water, 3 tablespoons of vinegar and some pieces of citrus peel in it. Run your microwave on high till it steams up inside. You can then clean any cooked on food and wipe it out. Boil the mixture a bit more after to remove any remaining scent.
Clean inside thoroughly with Hydrogen Peroxide. Then place a bowl of spent coffee grounds and leave for about a day.
pour half cup of white vinegar in microwaveable bowl or cup and run for 45 seconds then wait a few seconds and do it again it will remove odors
do not put chemicals inside the microwave including peroxide since you will be cooking and heating food in it