You can certainly clean you oven yourself.
The first thing to do is to determine if your oven has a self cleaning feature.
If the oven has a self cleaning feature the oven will heat to a high temperature and burn the residue inside your oven, turning the carbon build-up onto ash. Once the cleaning cycle is complete and the oven has cooled, you simply take a damp cloth and wipe out the oven.
If there is any build up that remains, you can clean the oven further, just as you would a non-self cleaning model.
When cleaning a non-self cleaning model you have 3 main options: vinegar and baking soda, ammonia or commercial grade oven cleaner.
Before applying any cleaning solution, make sure to have the following supplies on hand: rubber gloves, mask (particularly for ammonia and commercial grade oven cleaner), cleaning towels, plastic scraper and newspaper.
Remove racks from the oven, and if your model has metal rings on the stove top, they can be cleaned during this process as well.
Option 1: Vinegar and Baking soda-make a past of vinegar and baking soda and/or make a spray bottled solution of vinegar and baking soda.
After the oven has been wiped of extra residue, place a layer of paste inside the oven, both on the metal interior and on the glass face. If there is excessive carbon build up,