Email:
customerservice@ultrasabers.com or
marlena@ultrasabers.com (she's one of their best CS reps).
Upgrade will most likely involve a change in the battery setup from AAA batteries to rechargeable Li-Ion batteries. So I recommend getting a Li-Ion battery charger if you don't own one already. The XTARs that are sold in the shop are great!
And the LED will be swapped for a multi-die LED module - either RGBW or RGBA, depending on your preferences. White is excellent for bright Pulse and FoC effects, Amber is great for creating warm colours based on Red, Orange or Yellow.