Hi Melissa, welcome to planDisney!
I am so sorry that your plans changed, but I have good news! You can certainly change your theme park reservations to another date. I can walk you through the steps!
First and foremost, I would double-check the expiration date of your tickets, so you know how long you have to use your tickets. The easiest way is to load up your
Disneyland Mobile App, click the three horizontal lines in the bottom right-hand corner and select "Tickets and Passes". You should see your tickets along with their expiration dates! If you don't see your tickets there, then you'll need to link them to your account. You should see a "Link Tickets & Passes", and that should take you through the steps to link your tickets. Once your tickets are linked, you should see your tickets there along with their expiration dates.
The next step is to cancel your current reservation. You’ll need to log in to your
Disneyland Resort account, select the "My Disneyland" link, and then click the "Ticket and Reservation Details" link. Select the reservation you wish to cancel and click "Cancel Reservation". You'll then be able to select the party members who need to cancel. Once canceled, you're free to go ahead and book your new reservation!
Hope this helped, and if you have any more questions, please visit us again!
See ya real soon!
Jin