Classic/Antique Car Repair: Head light switch, headlight switch, small spring

Question
On a 69' Chevy C10 Pick up truck- Trying to replace the headlight switch next to the instrument cluster, I'm pretty sure I broke the replacement part trying to push in the nob. Now the nob just slides in and out and the lights don't work. I'm 100% sure it's the headlight switch is bad- Is there some trick to installing this part?

Answer
On the back side of the headlight switch, opposite the wires, there should be a small spring loaded button. Remove the headlight knob, reach under the dash and press the spring loaded button and then slide the knob in all the way. Then release the button and the knob and shaft should be locked in position and should work. If this does not do the trick then the headlight switch is damaged.
Brad