B&M Shifter Neutral Safety Switch

How do I wire the neutral safety switch on my B&M Starshifter?

Those are tiny little microswitches. They cannot- in my opinion anyway- sustain the necessary amperage for a solenoid. Here's what I do on any rod that uses a B&M shifter: the switch is used as a ground path. You will use a Bosch or simular quality 30/40 amp relay. From your ignition switch 'start', to the '30' leg. From the '87' leg, to your starter. For the '86' leg, you go to some ignition sourced feed- maybe from the ignition switch itself. Do not go to an accessory line- accessory normally is inoperative during cranking, and don't use a battery feed, because the relay be hot all the time the car is in park and drain the battery. The '85' leg goes to one side of the microswitch, the other side of the microswitch goes to ground. On all of the B&M shifters made this way, at least the ones I've seen, the two switch terminals you use will come with connectors attached. If this isn't the case, or you've removed them, you'll want the 'COM' and the 'N/O' terminals.