You can register Rey theme through several ways. You will however need the purchase code before you start. How to get a purchase code?
Setup wizard:
Right after you activate Rey theme the first time, you should be redirected to a setup wizard. You can find the registration form into the first step.

Rey Dashboard:
If you’re not already registered, in the Dashboard page, you should see the registration form in the first box.

Manual:
Open wp-config.php with your favorite editor and inside it, say – before or after define('WP_DEBUG', false);
, please add the following constant:
define('REY_API_KEY', '00000000-0000-0000-0000-000000000000');
Deregister
If you want to deregister, access Rey theme – Dashboard and in the first box, you should see the “DEREGISTER PURCHASE CODE” button.
