Quiting smoking is tough for people. It's not their fault though, Nicotine is addictive substance. Step one to quiting is not buying them! And not keeping any around or on you! Also Switching to the chew tobacco isn't a real solution, perhaps it takes the stress off your lungs, but your still addictive and you can still get mouth cancer.
First the substitution method by chewing gum instead of smoking and keeping like a pen in your and to play with in replace of a cigarette. Also big thing to do is stay away from people who are smoking. Don't hang around with your co-workers on their smoke break, they will offer you a cigarette and it will be very tempting. If they invite you to smoke, do not tell them you are trying to quit and are busy and cannot take a break.
The Expensive Method
there are things you can buy over the counter such as the nicotine patch, or nicotine gum. If you can afford them go ahead and try them, but know they are expensive. Also know these products are made by the cigarette companies, that perhaps don't really want you to quit and maybe why the products are so expensive? It's not rocket science, but they know that nicotine is addictive and you smoking makes them money.
The Doctor's Cure
Times have changed and we know have that magic pill you have all been asking for. Well not quite maybe, but close. There are medications that your doctor can prescribe for you that will in fact help you to quit smoking or at least to smoke less. It has in fact helped many people already to quit smoking. So if you are really intent on quiting and having a hard time, see your doctor and ask him about it.