What is the easiest way to clean an oven?

Fill a small glass bowl with 1/2 cup full strength ammonia, place in oven and close. Let stand overnight, then wipe loosened dirt with paper towels or newspapers. If then necessary, rub surfaces with a suitable abrasive, such as fine steel wool or soap-filled steel wool pad, wiping off "suds" with paper towels. Then wash with warm soapy water and rinse. Repeat the process if necessary.

Commercial oven cleaners are helpful if ovens are very soiled, but they should be used with caution. These cleaners can damage surfaces outside and around the oven. Be sure to protect these areas with layers of newspaper or other materials and cover your hands with protective gloves. If using most commercial oven cleaners, never spray in a hot oven (over 200 F.) which will make it even more caustic and can corrode surfaces. Never spray on oven light, electric elements, or pilot light in older gas ranges. Turn off the pilot light when using spray oven cleaners.

Removable parts, such as broiler pans and racks, can be cleaned more easily if allowed to soak in a sink or pan of sudsy water to which a little ammonia has been added. A lot of soaking is better for the surface, and easier, than a lot of scrubbing. Never soak aluminum in ammonia or other alkalis.

If necessary, you can scour oven racks or porcelain enamel with steel wool or a scouring pad to remove baked- on grease or food spills which have not come off in regular cleaning. Occasional use of such abrasive pads, or scouring powder on badly baked-on soil is OK, but don't use these too often or scrub too hard for you can scratch the smooth surface and make it harder to clean from then on. Do not scour mirror-finished metals, glass, or baked-on enamel.

[Info from the Home Maintenance And Repair Database at the Michigan State University website]

all you have to do is grab and kitchen cleaner like ones 4 the floor or dish soap and scrub 4 about 10 minutes.