To update your address you can login to your account and visit the 'Account Details' section. On here if you scroll down you can see the address boxes where you can place the new address.
If you are either filling in the registration form or updating your address on the account page and the address you are using cannot be found, please submit this form and include the new house number/name and also the postcode.
Your email should be the email that you registered with
If you are still having troubles with this then please visit this link. After entering your email address and clicking the Submit button you should receive an email allowing you to change your password.