How do you replace headlights in 1986 C10 Silverado?

It should be fairly easy, from the front of the vehicle there should be some screws that hold in the plastic casing, I think they are the star wrench screws. You should be able to take off the plastic piece just around the headlight and blinker unless it is a dual headlight. Once the plastic piece is off the headlight has a thin metal rim around it that has scews in it as well. Remove those (careful that you are not turning the headlight adjusting screws) and the headlight should come out and then you just unplug it, plug the new one back in and put everything back together.