How can I replace/amend referee details?

On your submission page, click on the references box. If your recruiter has only requested references from you, your submission page will automatically be set to the reference section.

Referee details cannot be amended once you submit the request, so if you need to make any changes you will need to delete the request by clicking the bin icon on the right-side of the request and then click the "add another" button to add the referee again with the amended details.