If you use a GM 1-wire, just connect the red Bat wire from the alternator to the battery (or horn relay as in the case of a Corvette) and make sure the case is grounded. You can also run a ground wire to the case as back-up.
Just disconnect the other plug/wires (the Field and Lighting Boost) at the alternator, and let it hang or cut the plug off the wires and tuck them back into the loom.
On a GM the plug on the voltage regulator can remain or you can unplug it. In the case of a Corvette (the basis of my experience), there is a "condensor" attached at the voltage regulator that you would disconnect if you pull this plug off the regulator. But the condensor is only for radio noise suppression and doesn't affect anything else and you may not have it.