Bright suns, Tiffany! Thank you for taking the time to send in your question to planDisney!
Savi's Workshop is located on the Outer Rim of the planet Batuu in
Star Wars: Galaxy’s Edge, and it is here where the Gatherers operate a workshop in a hidden backroom. I'm sure they are already anticipating your arrival!
Guests may cancel their Savi's Workshop booking if their plans change; however, cancellations must be made at least 24 hours before the reservation to avoid a per builder cancellation fee (charged to the credit card used to make the reservation). Simply sign in to your Disneyland account under the "My Disneyland" tab, and click on the "My Dining And Activity Reservations" link. Next, you should see your "Star Wars: Galaxy's Edge Savi's Workshop - Handbuilt Lightsabers" reservations. Since they are separate bookings, select the "Cancel Reservation" link associated with your 6:30 pm reservation.
Tiffany, picking out your Kyber crystal is the highlight of the experience, and the Gatherers will help you select from four different color options; red, blue, green, and violet. These Kyber crystal colors will also be the color of your lightsaber blade. Once you're done, you'll leave ready to take on the Empire as a newly forged Jedi. May the Force be with you!
Eean