Hi,Welcome to justanswer.
Please follow the steps to change the card info:
Go to amazon.comLog 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.
Follow the instructions below to update your email:
Visit http://www.amazon.com and sign in by entering your current e-mail address and password.Click on "Your Account" from the pull-down menu on the top right hand sideScroll down to the "Settings" section and click on the "Change Account Settings" link.Click the corresponding "Edit" button.Once you've made the updates, click "Save Changes".Now log into your account at http://kdp.amazon.comClick "(Your name)'s Account" at the top of the page.Scroll down to the bottom of the page and Click "Save" to confirm the change of email address in your KDP account
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