I would troubleshoot the system to find out what the problem is before "adjusting" switches. You can bypass (jumper) the neutral safety switch to test if it's defective but you have to know whether the switch is normally open or closed and be 100% sure the transmission is in fact in neutral to prevent it from starting in gear and someone getting hurt. You need a manual with a wiring diagram. If you can't find a Haynes Manual at an auto parts store or order it here:
http://www.haynes.com/products/productID/242