Hi Allison ~
Love your name!! I feel the force is strong with your young Padawans and I'm glad that they are preparing to defeat the dark side.
When I have taken my boys to register to participate in
Jedi Training: Trials of the Temple, registration began as soon as Disney's Hollywood Studios opened for the day. That included morning Extra Magic Hours. That policy can always change without notice, but that has been my experience.
If you are staying at a Walt Disney World Resort hotel and plan to go Disney's Hollywood Studios on a day when morning Extra Magic Hours are offered, I would recommend being there as soon as the park opens and head straight to register. Jedi Training: Trials of the Temple is a super popular experience for kids ages 4 to 12 years old and sign-ups are on a first-come, first-served basis.
Registration is at the Indiana Jones Adventure Outpost which is located between the Indiana Jones Epic Stunt Spectacular! and the 50's Prime Time Café. All of the kids in your party that want to participate will need to be with you when you go to register so be sure to have them together. The Cast Members will ask them a couple of questions to make sure that they can follow some basic instructions. Registration has always gone pretty quickly for us and we've never spent more than 20 minutes to complete the process.
Please feel free to visit us again with all of your planning questions. We will be hEAR for you until you embark on your pixie dusted trail!
Wishing you minnie magical memories :-) Allison V.