Edit your credit card information at billing.yahoo.com. You'll be asked to sign-in again to confirm your identity for this password-protected page. When it opens, click Update in the "Payment Method" column beneath the card number you'd like to change.

When you're done updating information, click Continue to save your changes.

Note: Any changes you make to your credit card information will automatically be applied to all your future payments for all your Yahoo! Premium Services.