It's easy to clean your oven using commercial oven cleaner spray. Make sure to wear rubber gloves and eye protection if using oven cleaner. Read all product instructions and follow the manufacturers directions.
First heat the to 200° . Turn the oven off, and take the spay and completely spray the soiled areas.
By heating the oven slightly, you give the cleaning product a power boost and it will do a better job at removing the baked on grime. Let the cleaner work over night.
Take a damp rag or sponge and simply wipe the grime out the next morning. Rinse the oven thoroughly then wipe it dry.