Do I need to call a repair person for this?

Have you tried removing all the racks and then pulling up on the pan that separates the oven from the burner area. Most of the pans come up and out rather easily. Taking the back off will give you access to practically nothing. There is a wall of insulation surrounding the oven . Removing things that you are not familiar with is a pretty sure way to guarantee that the next call you make will be to a repairman to put it back together and/or replace what ever you broke taking it apart.