How can I replace the element on my TB 650x Cooker?

Spares here:
http://www.espares.co.uk/search/mo620854pt1595/cookers-and-hobs/elements/tricity-bendix/tbf650x

Plenty of guides and videos here. If there's not your exact model, there should be enough similarities.

Take your time, make sure the cooker is turned off at the wall. Have a couple of pots handy to put screws in. Use screwdrivers that actually fit :-). Use pen and paper to note where screws go and how things go together - don't rely on memory.
Make sure you know how to reset the clock/timer afterwards - a lot of ovens wont work without that.

Give yourself plenty of time. Work slowly and methodically and think things through.

XXX
February 2017