You can update a customer’s email address in Passenger Cloud.
To do this, log into Passenger Cloud, search for the email address that they currently use in the 'Find a customer' search box. Then click on the “Change email address” button which is situated underneath the email address listed under the customer's account.
You will then be taken to a page asking you to enter a new email address, once this is entered, press the 'Save' button for the change to take effect. This will also update their email in Stripe automatically.
Once that’s done, you can advise the customer to log out and then back in again with their new email. Their password will not have changed.