Neutral Safety Switch Allison MD3060

Help. I have a 1993 Vectra with the MD3060 6-speed Allison. The key will not always start or engage the starter. I replaced the ignition switch and had a new solenoid installed on the starter and had it tested.

When it doesn't start, I get no power to the solenoid. (The small wire from ignition) I believe it is the neutral safety switch. Where is it located and can I do the job. I do most of my own work. And on this engine and transmission, could I bypass the switch. Any help would be greatly appreciated.