Its really an tough situation. Explain him that he would die if he continues to smoke. When I was a smoker I suffered a lot because of various health problems. Later I consulted a good hypnotherapist from http://www.thoughtsbecomereality.co.uk.
After trying various hypnosis sessions and hypnotherapy courses I found a tremendous changes in my self confidence and self control. So, I can suggest to take him to hypnosis from the mentioned site.