Good day Kaoru!
A very warm welcome to planDisney! Thanks for dropping by with a question!
Let me explain the steps to modify your
Theme Park Reservation. But first, because reservations are limited and subject to availability, I recommend checking the
Availability Calendar before you attempt to change your reservation. This will allow you to confirm your desired theme park are accepting reservations for your ticket type on your new date. Once you’ve confirmed availability, you may modify your Theme Park Reservation by logging in to your
Disneyland Account and selecting "My Disneyland." Then, click "Ticket and Reservation Details" and select "Cancel Reservation." After you receive the confirmation of cancellation, you’ll be able to book a brand new theme park reservation for your desired date.
Thanks again for stopping by planDisney with your question!
Tiffanie