Which element for starters? Fan Oven? Grill? Conventional Oven? Etc?
Is the element actually available?
https://www.espares.co.uk/search/mo929699pt1595/cookers-and-hobs/elements/tricity-bendix/dsie456w
https://www.espares.co.uk/product/es1248464/small-ceramic-hob-hotplate-element---1200w
There's more pages for the various specific elements on that website. Some have generic how to videos usually towards the bottom of the page.
Make sure you are working safely. Switch off at the wall and in the fusebox. If yours has a removable cooker circuit fuse, remove it and put it in your pocket.
Don't rely on memory for how things fit or which wire goes where. Have pen and paper handy. Label wires.
Gghj, January 2023