You need to observe whole process without judgment and opinions. As you smoke just observe it, ask "who smokes?", "why smokes?" and keep still mentally. In order for change to happen you must transcend that mental level on which you started a "problem". Be very conscious, don't let mind to tell you things like " iam bad" or "iam good", just watch the process. Observe. Please try. Don't think about time at all or whether you will be able to stop smoking or not. Just with pure childish interest observe what is going on. That observation itself will bring an insight upon which the mind will drop it itself.