L.M.
I quit seven years ago and I remember thinking, "Wouldn't it be great if there was something you could hold and puff on like a cigarette, but instead it was a breath mint!?!" So I went online and found this.... http://www.ezquit.com/
It was very important to keep my routines close to the way they were. When my work buddies would go out for a smoke, I would join them and take my "falsie." When I was at home, I would still go outside from time to time and instead of sitting on the front step and smoking a cigarette, I would prune my rosebushes or rake leaves.
Primarily, it is important to remember that nothing and no one will be able to MAKE you quit if you're not ready to do it for you. Also, like any other addiction, relapse is a part of recovery. Don't get down on him when that happens. Instead celebrate that it is one more step taken to being a "former smoker."
Also, I never lie to people who want to quit smoking and ask me how I did/do it. The truth is, I enjoyed smoking. To this day, seven years later, I miss smoking. Not every day anymore, but there are times where there is just a sense that something is missing.... incomplete. Then I look at my hand and realize I am holding those two fingers just slightly apart and realize the Ghost of Cigarettes Past is inhabiting my right hand. It is important to be realistic. It is great he has a supportive friend like you to help.
Also.... I found a website that calculated the cost of my habit and would send me periodic updates on how much money I was saving by not smoking. That was a great motivator to keep me going!