There is an easy way to adjust the switch. You will notice that there is a hole through the plastic pin that engages with the shift lever mechanism. When the switch is in the 'N' position this hole lines up with a hole in the switch housing.
So, with the shift selector in 'N', rotate the switch so that a 4mm pin can be inserted through the hole in the pin and into the switch housing. Tighten the two screws and you are done.
This information is in the transmission repair reference material.