The two hurdles are the cravings for a cigarette and the association with repeated actions. You get over the cravings first and within a relatively short period of time, 10 weeks or so depending on your own personal make up.
Associations, where you feel you should pick up a cigarette at any particular point last much longer. For example, I had not smoked for 10 months and had worked through all the associations, eg when the phone rang, after a meal and so on but I got on the ferry in Hull and watched them cast off and felt I ought to be smoking a cigarette, like I always used to do at this point every year.
The associations are not too hard to resist but you have to remind yourself, 'I don't smoke anymore'. You must avoid getting into thinking, 'I have given up, just one won't hurt'. Each and every association, and there are usually a large number of them, have to be broken one by one. Coming back on the ferry from Rotterdam, I didn't have the feeling because I had broken the association. The next time I got the feeling was when I flew somewhere and, normally the first thing you do after landing and getting through immigrations and the bag pick up is, go outside and have a cig. That was two years after giving up and I hadn't thought of a cigarette for a long time. But, they are not cravings, just habits learned in the past.
Best of luck with phase 1 of your quest. It is the harder but it does get easier every week. Don't get downhearted when you get the habit thing. You have many to break but each one is much easier than a real craving.