While baking a batch of blueberry muffins, our daughter dumped the entire pan onto the over door. The batter poured inside the door and we are trying to find a way to get the door off to clean the glass. We removed all screws around the door but the panel still won't come off. We also checked the manual but there's nothing in it that helps. Any suggetions on how to get the door panel off so we can clean the glass inside? Thanks.