welcome to CPF
there isnt much in way to modify the myo and if you were able to the plastic housing the light is in wouldnt deal with the heat very well and the light would probably over heat and fail.
I replaced the Lux III star in my Myo XP with a U bin I got from Photonfanatic. I very nice upgrade in color and output. Not too hard to do, either, as I'm not the greatest modder in the world.