To update payment information:
1. Login to the customer portal.
2. Click the Payment Methods tab.
3. Click Add new payment method and enter the payment method details.
4. Click the Subscriptions tab and click Edit on the subscription to be updated.
5. Expand the Shipping and Billing section and click Use this shipping and billing pair to select the new payment method.
6. Return to the Payment Methods tab, expand the old payment method and click Remove payment method.