I smoked from the time I was 13 (!!!!!!!!) till I was 35, and was up to nearly 3 packs a day. I quit cold turkey and never smoked another one, (And it's been 10 years!) but I think there are a lot of ways to do it that work. For myself, I just had to realize that I was going to feel really bad for a few weeks, but it wouldn't kill me, and that I would be getting occasional cigarette urges probably from the time I quit, on. Quitting wasn't nearly as bad as I had it pumped up in my mind to be. But even now, on the rare occasion, the cigarettes that usually stink so bad attract me (usually when i'm outside, and the cigarette is 15 feet away so I can just smell it a little). I knew ahead of time this would happen. and I've just made it a rule to NEVER actually ask for even one. I can't imagine that if I smoked one here and there, it wouldn't eventually turn into a fulltime habit again. Just know...even after a really long time, the urge can hit you; be ready to say, NO.
Good luck to anyone trying to quit, you can do it!