I smoked in my early 20's. I have pretty strong willpower, so I really just decided that was it and I did not smoke after that again. It was hard, especially the first couple of weeks, but if you can get thru the first couple of weeks, your friend will be fine. You really have to want to do quit. I really did not want to smell like smoke anymore; and I knew it was bad for my health so I decided and went cold turkey. I have to admit that into my second week, I bought a pack of cigs, lit one up in my truck and went uGGGG. It tasted terrible so the only time I have ever littered intentionally in my life, I threw the pack of cigarettes out the window and never lit up again!

I think it helps if you try to change your lifestyle at the same time you quit smoking. I know if I was trying to do something aerobic in my life, it would have helped me quit smoking. There are also all the tricks, nicotine patches, and hypnotism if just wanting to stop doesn't work.