Need to change your iTunes Store payment method? Perhaps you need to update your credit card information or turn a paid account into a free account (one without a credit card). Or you may simply want to check your account information. Here are two ways to accomplish this task.
On the iPad
Go to the App Store.
Select “Featured” (star icon) from the menu at the bottom.
Scroll down and choose “Apple ID” (lower left).
Choose “View Apple ID” from the pop-up menu.
Enter your Password.
Then choose “Payment Information” (second item).
On your computer
Change it in iTunes.
Select “iTunes Store” in the sidebar on the left.
Look for your Apple ID in the upper right (the email address for your iTunes Store account).
Click on the email address.
Enter your Apple ID (account) password.
You’ll see an account summary.
Look for “Payment Type” on the screen.
Select “Edit” to change your payment option.