Payment settings can be changed in the store where the payment method is registered.

App Store:

1. Open Device Settings -> tap iTunes & App store
2. Tap Apple ID email address and click view Apple ID (A message saying Login to your account might pop up)
3. Click Manage Payments. The family organizer can change the payment information with family sharing.
4. Change or delete your information. Click Remove to delete the payment method.
5. Click Done.

NOTE: Changing the payment method may cause the payment card to temporarily hold the approval for a short period of time. (iTunes checks if the new payment account is activated.)

Google Play Store:

1. On your phone, go to the Google Play Store.
2. Tap Menu (on the left) -> Payment methods
3. Go to More payment settings, and if asked, sign into your google account.
4. You can either delete or change the selected payment method.
5. Make your updates.
6. Click Update.