Remove the screws marked A in your diagram. This will allow you to remove the drum & backing plate (the element is attached to the backing plate). The 3 screws in the middle are for the bearing, which does not need touching at all. Nut marked M needs to be undone once you have removed the drum/backing plate out. Take extreme care now you have the drum/backing plate off. The nut marked M is removed, & carefully take note as the backing plate will come away from the drum, taking care to note there are spacers inbetween the backing plate/drum. The other end of the bolt, which is accessible from inside the drum, could have some tape put over it to stop it falling out. The replacement of the element is easy, just grind off the top of the rivets which hold the element in place, replacing the new element in the same way as the old element was fitted. I use steel rivets & (to fit the head of the rivets - washer) to put things back in place. I cannot stress the importance of being aware of the spacers inbetween the backing plate & drum - make sure they are in place as per original.
Glenn
July 2009