Disney will charge your cc one nights rate plus tax. When you go to add the package, they will have to re-book the room. They will refund your deposit from the room only package, then you have to place a deposit on the package that was just booked in its place. One thing that I am not sure of, and hopefully someone can clarify this.....when you do re-book the room for the package to be added on, what is the deposit total then? I know Payment in full is due 45 days prior to your arrival, but I wasn't sure what the package deposit is. I guess I didn't ask when I booked my room only, because by the time I add the package, I will pay most of my total, so I wasn't worried about what the deposit would be.