How do you change Chevrolet truck headlight?

depends on the year, but on the newer models its super easy. open the hood. right above the headlite you will see an "L" shaped bar. its about 1/4" in diameter. that's the locking pin for the headlite. unlatch it and slide it to the side and out. you will be able to tilt the whole headlite forward, giving you access to the bulbs and their connectors. undo the connector on the faulty bulb, twist it out and replace.

simple. no need for even reaiming.