You can change it just about at any time, but just be aware of the following.
1. You need a Credit Card to book your stay. That CC will be charged for 1-Nights stay upon booking.
2. When you check in, your credit card on file will be charged for the balance of your stay. If you want this on the same card, fine. If you decide you want this on a different card, change it before you check in.
3. Your active credit card can remain on file for your on-site charging previliges. Depending on the resort, a room credit limit is established. If during your stay, you get close to your limit, you will get a call from Front Desk and they will run that amount to your card and reset your limit.
4. If you do not approch your limit, your outsanding balance will be run during the night BEFORE your departure. If you wanted to pay cash, or use a gift card, or change the CC on file, be sure to do it the night before your scheduled to depart.
SIDE NOTE: All Ticket Purchases are paid for upon purchase. But, if you do not want to charge it to the room or CC on file, just tell the Concierge before they proceed.
I think that covers almost everything........