It only takes 3 days for the physical addition to leave, after that it's only the mental addition.
Knowing that I used the "cut down about 5 cigs a day less for a week" approach. I just kept cutting back each week until I was down to just a few hits a day and they didn't appeal to me any more after that. It worked for me and it's been over 20 years. It will only work if you are truly motivated to quit.
Note: try not to drink coffee or alcohal during this period, or anthing else that stimulates more smoking.
Goood luck.