I have the same problem with the rear heating element on my Smeg oven. It has been replaced twice in about 6 years, so I thought I would do it this time myself and save the cost of a repair man. It was easy to take off the top and side panels and expose the fan and rear heating element. But the phillips head screws on the rear heating element are jammed tight. I have had to drill one of them out. Unfortunately a piece of broken drill bit is jammed in the other screw. This does not seem the correct way to do the job.
If you have solved your problem please post the answer as I need the same help.
Ta
Help-please, October 2009