To update your card information, you will need to navigate to the 'My Apps' section of your account: https://www.cybrary.it/myapps (shown below)
Select the App you would like to update. After selecting your app it will take you to a screen like the screenshot below. Under the green launch bottom, there is a link to 'Manage my Purchase.' You can edit your card information and billing address there.
After selecting the embedded link in "here" you will be taken to a page to edit any billing or card information needed.