Sigh, that's one of the things I bugged them about. I just gave up.
Anyway:
1. Log inside your account.
2. Click Account Manager => Renew Services.
3. It'll show a list of services and whether they're set to renew monthly, yearly,
or not. Click Annual beside the item/s in question.
4. Click the radio button/circle beside "Turn It Off".
5. Hit Save.
For monthly services, you have to call them.