Be logged in and use the deletion link named here.
URLS:
http://www.theregister.co.uk/
http://account.theregister.co.uk/delete/
Please note that AccountKiller.com is not associated with the business listed on this page. AccountKiller provides easy-to-understand instructions and guides on how to cancel charges and relationships from the list of businesses on our site, we have no affiliation with these businesses.