1. Go to the Salesforce AppExchange.
2. Login with your production Salesforce credentials.
3. Click on your profile picture and select "My Installs & Subscriptions".
4. Click Manage Subscription for Blackthorn Compliance.
5. Click Edit on the bottom right of your screen.
6. Click Edit Payment, and enter the new credit card
7. Click Review Changes.
8. Click Save.