If it is anything like the Belling E665, you need to take both sides off. This requires removing the two screws at the rear and the two screws at the front. For the front side where the oven door is hinged you need to remove the oven door to reach the lower screw. Once the sides are off you need to undo the now accessible screws at the side holding the top, and the two screws at the rear. The top will now lift off and replacing the element is staightforward.
Art Couper, February 2010