Hi Jernelle! Welcome to planDisney!
Are you SO excited to
visit the Walt Disney World Resort soon? It sounds like you have been busy planning out your days and I'm happy to hear it. There can be a lot of planning that goes into preparing for your vacation, but once you are there and enjoying all that the theme parks have to offer, it will be worth it!
When it comes to changing theme parks with
Disney Park Pass reservations, you are welcome to change from EPCOT to
Disney's Hollywood Studios as long as there is reservation availability to make the switch. I have changed theme parks up to the day before my reservation. It is nice to have the flexibility to alter plans when you decide you need an extra day at one of the theme parks or you change your mind!
Before canceling your
EPCOT reservation, I recommend taking a look at the
Theme Park Reservation Availability calendar to make sure there are still reservations available for Disney's Hollywood Studios. If so, go ahead and make the switch. Looking at the calendar now, it looks like all four theme parks are available for September 6, 2021, but that can change at any time so it's a good idea to check right before you change your plans.
I hope this helps, Jernelle! Please let us know if you have any other questions.
Tabitha