1) Go to the Premium Shop, click on your email in the upper right corner and choose 'Manage Subscriptions' from the drop-down menu:
2) In the next window click on the Premium Subscription button to learn more details about your subscription:
3) To hold or cancel your subscription scroll down to Subscription Details and click on 'Hold or Cancel' button there
4) In the next window choose preferable option:
Warning! The operation is final, you won't get any additional window and you can't reverse this action.