Wipe around the edge of the door and the 1 ½ inch area surrounding the inside frame of the oven cavity. Use a damp rag to clean this area. Avoid getting water in the slots on the door frame. Dry the area with a clean rag.
Fill a bucket with 1 qt. of warm water. Add ½ cup ammonia.
Scrub the inside of the oven glass with a sponge and the ammonia solution. Wear rubber gloves to prevent skin irritation from the ammonia. If the buildup is heavy, toss the ammonia-soaked sponge in the microwave for 10 seconds to warm it, then use it to scrub away the buildup. It may be necessary to let the ammonia sit on the glass for five minutes to soften the buildup.
Rinse the glass with a damp rag and dry it thoroughly.
Spray glass cleaner onto a few paper towels and clean the outside oven door glass.