How to Replace a Headlight
Learning how to replace a headlight all depends the type of vehicle in question, as well as the year it was manufactured. Most modern vehicles have a headlight assembly, which is a self-contained collection of such parts as the housing, reflector, bulbs and the base, all in one unit. This is both convenient and troublesome at the same time; without a shop and professional tools, some assemblies may prove nearly impossible to work on or reach.
First: Know your enemy
The first steps to replacing a headlight are to determine how the assembly is put together, where it is connected and whether or not it is a sealed unit. Many newer models have hermetically-sealed air-tight lighting packages that cannot open; they are merely replaced as a single unit, which only requires disconnection and reconnection of the new unit. Identifying the parts you are working with makes understanding and tackling the problem much easier, and help is never farther away than the wealth of information online.
Second: Put in the new headlight
For the vast majority of car owners, all that is necessary is to remove a few screws on the housing. Then, simply unplug and remove the old bulbs and replace them with new ones. After that, return the assembly to its original location. Though it is usually quite simple to change a headlight on these types of vehicles, a misaligned assembly or a loose screw can often result in a light pointing straight up, down or off to one side. When you take your time and consult the documentation of your vehicle, it is usually enough to let you know whether or not you can tackle the problem on your own. For many cars and trucks, this is a very minor undertaking.