TO update your payment information for a registration that is being paid through installments follow these steps:
From a computer / laptop log in to the website at app.teamlinkt.com
Hover over your name / profile picture in the top right
Select 'Family'
Select the family member whose registration you need to update the payment details for
Under the registration tab click 'Update Payment Method' for the appropriate registration.
Enter new details and click 'Update'
All done! Your next payment will use the updated card information.