There's nothing to worry about. If we've confirmed your deferral with you, just wait until you're invited to re-register. You should get your invitation email a few weeks before your course starts and your login details will then be reactivated.
If your password has expired or you get a technical error message when trying to log in after this invitation, email our IT team on ITservicedesk@gre.ac.uk or call 020 8331 7555.