If your email address is associated with an existing ArtistWorks account, you will need to complete the order while logged into your username. You can log into the username before or during the checkout process. If you get lost, just go back to artistworks.com while logged in, select your course and proceed the checkout.
To renew with a discount, enter the promo code in the box during checkout and click "apply to order" to see the new price. Please note, the subscription will be set to renew automatically at the full price regardless of the discount you use during checkout.
If you have any questions or further issues please let us more about what's happening and where you're getting stuck.