Bright Suns, Mitchell!
We're so glad you decided to visit us at planDisney. I hope I can be the Droid, I mean... the panelist you're looking for when it comes to solving your lightsaber dilemma.
My children have been known to use more than a reasonable amount of the Force with their toys and intergalactic gadgets. They built Custom Astromech Units at
Droid Depot a few years ago, and let's say I had to contact Merchandise Guest Services on more than one occasion. We all had a good laugh when we realized the droids had an automatic power-saving battery, and we didn't have to replace the entire units on the third day of ownership.
Our family hasn't yet had the chance to experience
Savi's Workshop - Handbuilt Lightsabers but I'm sure we'll pay a visit in due time. I took a look at the parts list and saw that only the hilt, sleeves, emitters, pommel caps, activation plates and switches are named pieces. I'd recommend reaching out to
Merchandise Guest Services by email or phone to inquire about replacing your specific part. You'll be able to include relevant photos if you email them, but it might be a quicker process to call and discuss with a helpful Cast Member.
If you have an upcoming trip to
Star Wars: Galaxy’s Edge you can also inquire in person about replacement parts. While you're there, make time to tackle
Star Wars: Batuu Bounty Hunters as my friend Al, discusses in this answer. My crew loved racing around on our quest for credits during our last visit.
I hope you can get your son's lightsaber in perfect working order in time to aid The Resistance. If you have additional planning questions in the meantime, please don't hesitate to come back and see us again.
May the Force be with you,
Amy