The fan element, just to be sure you are on the right one, is situated behind the back panel inside the oven and is circular. It should be held in by 2 screws in the fixing plate and 1 screw on a bracket on the element opposite the fixing plate. be careful when pulling the element out that the wires do not come off so you know where they go. If you have hex bolts then they are not original and may have been put in by another repairer, and will have nuts on the back so the oven will have to come out to undo them.
Kenjo
August 2014