There is currently no option to restart your account as it is. The only option you have is to delete your account and create a new account. When you delete your old account you will also receive a voucher for any STARS you have in your account, so you will be able to use them in your new account.
To redeem a voucher, click the Stars balance in your account, then ''Redeem voucher'' and enter the voucher in the appropriate field:
It takes up to 48 hours until an account is fully deleted (,the earliest is the next nightly update). This means that you will have to wait until then to register a new account with the same E-Mail adresse. You can of course use a different E-Mail to sign up and change it later once the other account is fully deleted.