How to cancel the credit card bound when purchasing software on iPhone5

The operation of canceling the credit card bound when purchasing software on iPhone5 is:

1. Click "Settings" on the main interface of the device.

2. Open "iTunes? Store? and App? Store".

3. Click "?Apple?ID". If you are not logged in to your Apple account, you need to log in. (Please ignore if you are logged in with an Apple account)?

4. Click on the account to display the selection interface, and select "View Apple ID".

5. After entering the password, select "OK".

6. Go to "Account Settings", click "Payment Information", set up a bank card after entering, and select "None".