If you want to change the credit card that is charged for your monthly video plan:
Click here and sign in to the account: https://secure.oovoo.com/Signin.aspx?ReturnUrl=%2fMyAccount.aspx
If you want to update the credit card for Credit purchases:
The next time you need credits please place a new order with your new credit card; this will update your account with this number. Do not place a one-click order or you will charge the existing card.