Welcome to justanswer.
Is it for your kindle you want to change the credit card info?
If its a kindle then please follow the steps below.
Go to amazon.com(from your computer).Log in using the email id and password.Once you have logged in , Go to Manage Your Content and Devices.From Settings, select Edit Payment Method below Kindle Payment Settings.Select the desired credit card information, or add a new card, and then click Continue.Enter the desired billing address, and then click Continue. You will be taken back to the Kindle Payment Settings page where you can view your edited 1-Click payment method.
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