You may view and manage your subscription in the settings area, from the user menu in the top-right. Select the "Subscription" subsection in the left navigation menu. Here you will find your current subscription status, available plans, and current billing period.
To update your payment method click the "Update Cart" button, enter your new credit card numbers, and click "Submit Card".
Depending on your account configuration, you may find alternative plans in addition to your current plan. To change plans, select the new desired plan and click Save (top-right).
View your past invoices click the "Invoices" button.
In the event that you wish to suspend or cancel your subscription, you may do so by clicking the Cancel button. At this point, you will be asked to confirm and optionally provide feedback which is greatly appreciated.