to change the billing method for your existing hint subscription:
- login to your customer account at www.drinkhint.com, using the same email you used to set up the subscription.
- this should bring you to your Account page.
- click on subscriptions
- on the right side of the page you will see all your subscription flavors
- above the flavor click on "billing information"
- click "update card"
- enter the credit card information, to save click on the update card button