We have a Rosieres Paul Bocuse 4040 Range cooker which we inherited with the house. The lower element of the fan oven (left side) is not working. I’ve got the part (through UK Whitegoods) but can’t figure out how to get to it as the oven bottom can’t be removed from the inside. Does anyone know how it can be changed? Is it accessible from the back? Does anyone have a manual? We’ve managed to replace parts before and found it straight forward but need help with this one! Thanks.