Fill a clean, microwave-safe bowl with white vinegar. Alternatively, mix 1 cup of water and 1/2 cup of lemon juice in the microwave-safe bowl.
Put the vinegar-filled bowl inside the microwave and close the door. Cook the vinegar for five minutes on high. The vinegar will remove odors and loosen food, grease and grime from the microwave walls.
Remove the bowl from the microwave and wipe the inside of the microwave clean with a vinegar-soaked sponge.
Dampen a clean cloth in cool water and rinse the vinegar off the inside of the microwave. Dry the microwave with a lint-free cloth.
Repeat the process until the odor is no longer present.