As far as i know it is the wiring that is different,possibly another couple of bits and bobs also, definately not a straight swap, certainly not something id feel confident about doing myself but if you got a foxeye fairing and light unit at a decent price it might be still worthwhile paying someone to do the mod for you.
if you use the search function along the top of the forum you should be able to find previous posts about the mod to get you started, on the plus side you would also have better lights as they are far superior to the boxeye units.
cheers
fras