I have done something similar in the past in my Dummy Reference Guide to Minimag mod (see section 3b), and the lux III(J bin) seems to be working quite ok with the mod. I assumed the (G bin) might be a little overdriving it, but it should be ok to do.
The swapping on mine was quite easy, only grease under sink of the side emitter. One friendly advice, just make sure to remember the polarity before removing the lux.