Since the payment only goes through PayPal, the payment info is stored on the Paypal website.
to access the payment information for the subscription you can do the following:
  • Log in to your PayPal account.
  • Click Profile near the top of the page.
  • Click My money.
  • Click Update in the My preapproved payments section.
  • Click the name of the merchant for the agreement you want to change.
  • Click Change beside Backup Funding Source in the Funding Source section.
  • Select the payment method you’d like to use and click Save.
Paypal will use that updated payment information for the next recurring payment