You can update your payment method via your customer portal:

• You will need to go to the customer portal
• Enter your email address and select "Continue"
• A one-time password will be sent to your email address. Enter the One-time password into the respected field and select "Login"
• Once in the Customer Portal, select "Payment Method"
• Click on "Add New"
• Input your new payment method and then select "Add"
• Select if you wish for your new card to be the "Primary" or Backup" payment method
• Click Update