I'm not sure about how to cut down, that would possibly be even more difficult than quitting because you still give into the urge to smoke. As for quitting, one very simple, but effective, way is to never carry cigarettes with you. Then when you NEED to smoke you make a decision. Do you drive to the store for that one cigarette and then throw the rest away, or do you just deal with the urge and move on? Almost every time the urge will pass before you get to the store, even if you were going to give in.
The hard part of quitting nicotine is because it is not only a habitual addiction, but also a chemical addiction. Your brain "needs" it to function, as well as getting a rush of endorphins when you smoke. The two of those combined is a tough combination to beat.