If you have the Salesbolt Extension installed

Please note - for security, this requires you to be a Salesforce Admin, or have "Modify All Data" enabled in your Salesforce profile.

From the extension, navigate to the Billing tab via the Chrome Extension.

Then click the button "Update Payment Info".

This will take you to the Stripe Billing Portal, where you will see a link to "Add Payment Method" or to remove your current payment method.