A payment method can be removed from a customer by going to the customer dashboard and clicking on "Manage" in the Payment option block
Under the Actions, verify that the value is "Delete" and click "Go"
A confirmation pop-up will appear, click "Yes"
Note: The payment method cannot be deleted if it is the default payment method and the customer has more than one payment method. The following error message will display:
" Error deleting the payment method: Cannot delete a default payment method. Please mark another payment method as the default first."
In an account with hierarchy enabled, the above error message will also display if the payment method is being used as the default in one of the child account. The payment method of a customer can also not be deleted if it is the only payment method of a parent and it is being used by the child. The following error message will display: "Error deleting the payment method: There are Children using this Payment Method so it cannot be removed"
The parent-child relationship can be removed (no longer a child using the payment method) or a new payment method would have to be added to the child account.