In order to cancel a subscription, you will first need to reach your Customer Portal. When you first subscribed to your order, you should have received an email with your personal Customer Portal link. If you click on this link, you will be taken to your Customer Portal where you can manage all of your subscriptions - including cancel them!
Once you are in the Customer Portal, you will click the Subscriptions tab on the left hand side.
Then next to each of the products you are subscribed to is a Cancel button. You would use this if you would like to no longer receive this subscription product.