In the case that you wish to edit your credit card information, on the home screen of your subscription portal (details for accessing your subscription portal can be found here: How To: Manage Your Subscription, click on "Payment Method" and then click on "Edit".
Once you click on the "Edit" button you will be taken to the page where you can edit/add credit card information. On this page you can type in your new credit card number, security code, and expiration date. In the case that your billing address has changed, you can edit that information from the "Home" page of this portal.
Please be sure that the zip code listed under Billing Address matches the billing zip for your credit card. If the zip code doesn't match, we will not know until a charge is attempted.
When finished click on "Update" at the bottom.
Once your payment information is updated (and you've hit the 'Update" button) you will then be returned to the "Home" screen.