Hi Emily!
I remember when Walt Disney World Resort first introduced the original paper FastPass. It was all the way back in the last century, 1999, and back then you had to walk to a machine at each attraction, uphill both ways, and in the snow. Or something like that.
Officially, once your current
FastPass+ selections are set, you're unable to peruse for better options in the screen used to make your current reservations. However, there is a bit of a work around. From either a desktop or the My Disney Experience Mobile App, log in to your My Disney Experience account and get to your
'FastPass+ Reservation' screen. Find an attraction that you'd like to possibly reschedule or switch. Then, from a desktop click 'View Details', or in the app click the reservation. The next pop-up will list three blue options, and you'll want to select 'Modify'. (I promise for this next part we're just playing around with things and nothing is permanent yet.) A list of everyone in the reservation will pop up. You
can select just yourself, but the results given will then be for only one rider. So select everyone if you'd like to check on a new time for everyone, or select just a few people, whatever you need to do. Now you'll be shown a list of all of your other options for that park for that day. The first attraction listed will be the one you chose "to modify", with all other options listed below. If you do find a new attraction, or better time for your modified selection, that you'd like to change to, continue with the green button confirmation prompts and you'll be set!
If at any time you want to stick with your initial plan, just press 'Back' or 'Start Over' and you'll get back to the main screen of your original plans with everything still in tact.
We'll See You Real Soon, Emily!
~Kristen