Hello David,
Thanks for stopping by planDisney with your question.
It's so great to hear that you'll be enjoying the
California Resident Ticket Offer and getting to experience all that's cool at
Disneyland Park and
Disney California Adventure Park.
While theme park reservations for the Disneyland Resort
can't be modified directly, there is a simple way to cancel a theme park reservation and then make a new theme park reservation.
When you sign in to your Disneyland account, you can go to your
"My Theme Park Reservations" page where you can cancel your existing theme park reservation. You can then book a new theme park reservation for the day you wish to visit the theme parks based on reservation availability. It can be helpful to first check out the
Theme Park Reservation Availability calendar to check that theme park reservations are available for the dates you wish to visit the theme parks.
David, I hope this information is helpful as you make your plans to visit "The Happiest Place on Earth." Enjoy all the magic!
Jerry