Here you can purchase an upgrade for your existing 0 license to a 0 license.

Enter the Customer Number along with your License ID or Authentication Number for your existing 0 purchase. The Customer Number and Authentication Number can be found in your receipt e-mail you received when you purchased 0. The Customer Number and License ID can also be found on the About dialog in the 0 Administrator. You can use either the License ID or Authentication Number to authenticate your purchase.