From what I remember since this was done years ago on my car.
Isolated pin on alternator with 10mm nut should be an #8 gauge wire to battery. Small pin on alternator with 8mm nut (I think) is ground. 2 pin plug should have white-red wire which should go to the idiot dashboard light. Last one, which is either white or red is connect to 12v which will give you a reading on a voltage gauge if you have one.

You should be able to just unplug the external voltage regulator and leave it or remove it. Rap up the plug with electrical tape or work your way into the wire bundle and remove it.
Easy.