Hey there, Shannon!
If you want to modify the date of your theme park visit, you can absolutely do so without losing your current
Disney Park Pass system reservations.
What you will want to do is to first cancel the Disney Park Pass system reservations that you do NOT need. Then you will want to go into your
My Disney Experience Account and click "My Plans" and then "Tickets & Memory Maker."
Under where you see each of your individual
tickets, you should see a blue option to "Change Ticket." By clicking this button, you will be able to modify the dates of your tickets.
Once you change your tickets, you will then be able to make any additional Disney Park Pass system reservations for your new dates. While changing your ticket should not cancel your existing Disney Park Pass system reservations, you should always go back and double-check.
See you real soon!
Sarah B.