Isolate the appliance from the electricity supply first.
Inside the oven, remove the screws securing the back plate and remove the back plate.
This exposes the element. If it's screwed from there, take out the screws and carefully work the wiring through with the element as you remove it.
If it's not screwed from the inside, remove the rear of the oven and remove the nuts securing the element.
As they say in all the best programs, fitting is the reverse of the removal.
Good luck with your repair.