Just fixed the 10 year old Dualit for the first time. Someone bashed it and broke the neon indicator, and I also replaced one of the elements that was getting a little iffy. The securing nuts are 6.5mm - they will sell you a spanner! I used 4BA spanners which worked fine.
The amusing part was when I mentioned it afterwards, and someone pointed out that (according to the university's official wi-fi guidance) toasters can interfere with the wi-fi signal...I'm at a loss to see how any toaster could, but certainly not the Dualit...