I printed all parts in White ABS except for the LED cover, which is printed in T-Glase. you obviously want this to be as transparent as possible.
The batteries are wired with a heavy gauge single conductor wire. Place the wire through the small hole at the bottom of the battery contact. Place a small drop of super glue on the wire above the battery contact to keep the wire in place, making sure you don't get any glue on the contact itself.
Wire the negative terminal to GND on the trinket and the positive terminal to BAT. connect the 5v and gnd wires to the the same BAT and GND pins you just wired the batteries to. Connect the signal wire from the LED strip to output zero on the Trinket, although you could wire it to another output if you don't mind altering the source code. Make sure you run the wires through the hollow compartment in the handle. You can solder the wires directly to the bottom of the Trinket PCB to keep it nice and neat.
Remove the LED strip from the silicone casing and wrap the LED strip around the shaft of the wand, making sure that the strip is touching itself as you wrap it around. I used a few drops of hot glue to secure the strip to the shaft. This will allow you to take it off again if you want to reuse it.
Once you have verified everything is working, secure the cover to the handle with a little super glue.