Help replacing bottom element in Kenwood CK480

Although heating up, oven wasn’t getting up to full operating temperature when used in fan-assisted convection mode and I have diagnosed that the bottom element has died. I’ve taken the back off and checked the element with a meter and it is open circuit. Before ordering a replacement element, I have been trying to get the base panel out to see whether I can fit it myself (and to check what the element looks like for ordering) with no success.
Three screws removed from the front, three from the back, but no apparent way to lift/prise out the base panel, as it is held down by a wide lip at the front and is tight against the back panel. Looks like I might have to remove the circular fan element on the back panel to get the base panel out in any case, even when I have found out how to push/pull it up. Am I missing some obvious tricks? Any suggestions greatly appreciated.