If you change h/u you either need to:
- find a fiber optic h/u (there are a few as I recall)
or
- also replace amp
Set up (aside from fiber optic loop b/w CDC, H/U and amp) is same as any other audio system... copper wire from amp to drivers. That said, BOSE is sometimes known to do wacko things w/ speaker impedance so check the drivers first for compatibility w/ aftermarket amps. Even then, I'd consider replacing most of the drivers too.
BOSE = Great marketers of just ok sounding stuff (if you like it really 'boomy')
Good luck