To change a habit, the motivation has to begin with a deep and abiding sense of purpose, and your goal must fit into that big picture. So start by asking yourself, When all is said and done, what do I feel must happen for me to have lived a life of significance? Say it's that you want to be an extraordinary parent. If your challenge is exercise, then you can keep reminding yourself that you're not working out to be buff, you're doing it to be a great mother. You don't want to be short on energy; you don't want to come home exhausted. Once you get that connection to your ultimate mission, you have the holy grail of change.
Next ask what private voice you've been listening to—the one that keeps defeating you every time you try to reach a goal. What's the excuse it tells you? "I'm too tired to exercise"? "I don't have time"? Okay, but is that really true? What are you doing at 5:30 in the morning? Well, you're sleeping. If you really wanted to do this, you could engineer time. Identify this voice, challenge its faulty assumptions, and "out" it by getting it on paper. Once you sit back and read it, you'll see the negatives you've been letting run your life.
So what's the new story—the voice that is deeply connected to purpose, that makes you want to fight? We had a smoker who suddenly realized she went nine months during her pregnancy not touching a cigarette. She wasn't even tempted because she couldn't imagine hurting her unborn child. That story gave her strength. Think of yours as the epic of the great adventure in your life. Write it down and keep rereading it to retrain your mind.
Next comes the behavioral change. Design one to three rituals to help you get to your goal. For instance, if the goal is exercise, you're going to get up at 5:45 every other morning. Or when you want a cigarette, you'll take a drink of water instead or look at a picture of your daughter. It's always more successful to take an action (drink water) than to avoid one (not smoke).
As you put very specific rituals in place, keep going back to how it's connected to your being a successful human in the ultimate sense. Every day, fill out a log that says whether you did what you said you were going to do. We've researched this, and within 30 to 60 days, you will make it a habit. There's only one way that this will fail, and that's if you give up.