If you need to change the payment method that you selected for an upcoming random draw, and the entry window is still open, you will need to remove your entry and then re-enter with the proper payment information.
If the entry window is closed, you are unable to update the payment information tied to your entry. If your entry ends up being selected, but the charge fails, there isn't a way to go in and charge you after the fact, because the selection process has run and all bottles are accounted for, resulting in your entry not winning.