Tap Settings on the Home screen.
Tap iTunes & App Stores. Tap on your Apple ID. (If you are not signed in, enter your Apple ID and password, and tap Sign In.)
Tap View Apple ID.
Enter your Apple ID password.
In the Edit section, tap Payment Information.
Update the information that you want to change.
Tap the Done button when finished.
The payment methods that the iTunes Store accepts can be found in the payment type section. If you do not want a payment method on your account, select None in the payment type section.
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