This is a very simple mod that anyone can do. I could not find any clear directions online on how to fix the Altima headlight problem (lights only shine 60 feet in front of the car), so I did some digging around on my car while changing the oil. At a minimum you will need a screwdriver, but a jack will make your life a lot easier. I have my tire removed for the picture, but when the car is jacked it creates enough room that wheel removal isnt necessary. This process can also be used for changing the headlight bulbs too. (The oil filter has the worst location I have ever seen on any car)
1. Jack either the passenger or driver side, so that it will open the wheel well up so you can get in there easier.
2. Remove the plastic clips on the wheel well cover with the screwdriver, so you can pull the wheel well cover down and get to the headlights in front of the wheel.
(The yellow markings are where the most important clips to remove are located)
3. Pull the wheel well cover down like in the photo below. It will bend so dont worry about breaking it.
4. To adjust the headlight beam, you need to turn the silver screw (circled in the photo below) in a counter-clockwise direction to raise it.
5. Lower your car and check your beam height. When you get it to where you want it, put the clips back in the wheel well and you are done.