Go to Settings and then click on the Payment tab:
Add/Delete a Credit or Debit Card
If you want to add a Credit or Debit Card, please click on Add new card:
If the information is correct, you will be able to click Save to save your card information.
If you want to delete your Credit or Debit Card information, please click the Trash Can icon on the right side of the screen.
Go to Settings, tap on Payment Method, then tap on Add a new card. Enter your card information then tap Save.
To delete a credit card, simply tap on the trash can icon next to the credit card you'd like to delete: