The key to beating is in the change of the behaviors that surround it. Your initial week or two after quitting is indeed a physical withdrawal from the extra receptors your body has built to intake the nicotine. If those receptors are left to starve, they will die off and reduce in number to a point where there is no more physical addiction.
Then, the largest challenge is changing the behaviors that make someone want to go outside and smoke. People like to go to a bar and smoke. Some people pass the time driving and smoking. The opiates released during smoking give people such a temporary euphoric feeling that the behavior drives the desire to feel that way. Once someone can realize that those receptors are no longer there to accept the nicotine, they must find other ways or motivations to avoid smoking.
I know I am making it way simpler than it sounds, but if you understand the fact that you are not physically addicted after a short time and the rest of it is in your head, it can be very motivating to want to conquer yourself.