Here'* a good link for the Vats bypass.
I'm not sure if the white connector shown in that link is easy to get to on the Bonneville. If not you can just cut the wires but cut them in an area where there'* enough slack so they can be put back together. You'll find the wires coming down the steering column inside a plastic sleeve.
Here'* a trick you can try. After cutting the wires strip a little insulation off the ends going up into the dash. Now hold those wires to the metal contacts of the spare key & use the other key to start the car. After it starts you can let go of the spare key & the engine will continue to run. It should also restart without having to hold the wires to the key. You'll eventually want to solder in a resistor so the security light stays off.