Simple, go to
mydlink.com click on the "Storage" tab and select the DNR-202L, now, download the installation wizard.
Run the wizard and follow the steps to add it back to your account.
Warning: The mydlink® services have had some issues today that may interfere with the binding of devices back to your account... They are working on restoring the services, but not sure if that has been done yet. By the way, this is only affecting the USMP servers, so if you are in another part of the world, you should be fine.
If you are part of the USMP coverage, just be patient and wait a bit if you find problems binding the device back to your account.
Hope this helps!