smoking problem

Any suggestions how to quit smoking? I've been finding ways on how to stop the husband from smoking, but so far ... haven't found the right solution for him. I so want the husband to kick this bad habit out his system for years now but it seems he's getting worst every day. He used to consume five sticks per day, but lately he can finish one pack of cigarettes per day. Could it be caused by his stressful work? Very bad. And with his increase in cigarette intake, I am worried for his health. And he's not getting any younger ... he needs to be fit and ensure he's always on top shape. Hence, any helpful tips or suggestions how to quit smoking?