He's smoked for 30 plus years. That may sound silly, but it s true. You obviously need a strong internal drive to want to quit. I recommend that you try to think of something that will motivate him. Another good motivator is to discuss second hand smoke.
Kids are more likely to have asthma and infections when they are constantly around smokers.
When a smoker decides to quit it sometimes is helpful to do it on a special day, like a birthday or the millennium. This way it may have more meaning. Another important think to encourage long time smokers is that its never too late to quit. They would reap the benefit to their heart in only one year. It takes longer for the lung to recover, but it can.