^follow the silver arm that comes from your shifter. It goes to that sensor on te passanger side of the transmission toward the bellhousing that bolts to that actual transmission

 

Although this is an old post, most every switch has a small hole in it used to align the shaft and switch.

If the switch is removed, put it in either park or neutral and insert a small drill bit into the hole and rotate the switch until the bit goes in. Tighten switch in place.

Now place the transmission and interior gear selector in park and Tighten the adjustor on the arm. Inside the car, make sure all gears are selectable and the appropriate light comes on for each gear.