Why do 45 million Americans keep smoking, even though they know their addiction is killing them? The fact is, quitting cigarettes is just as hard as kicking a heroin habit.

The authors of the popular “YOU” series of books, Drs. Mehmet Oz and Michael Roizen, have created a four-step plan to help smokers break the deadly habit.

Over the next two months, “Good Morning America” will follow three smokers as they record video diaries about their efforts to quit, by using the doctors’ plan. You can follow their progress on the ‘GMA’ page of ABCNews.com

If you’re a smoker or want to help one quit, you can find Oz and Roizen’s four-step plan below, as well as other tips and resources.

YOU: Stop Smoking Plan

1. Identifying what kind of smoker you are. When is your first cigarette of the day? Do you usually smoke alone or socially?

2. Preparing to kick the habit. Day 1 of the plan begins one month before your actual quit date. Identify and avoid smoking triggers (do you smoke when you drink coffee, after meals, out at a bar?) Write down a list of reasons for quitting.

3. Breaking the habit. Talk to your doctor about anti-smoking treatments. There are drugs that target certain areas of the brain to stave off cravings or make smoking less pleasurable. You can also try nicotine replacement therapies, such as nicotine patches and gum.

4. Enjoying life as a non-smoker and avoiding relapse. Reward yourself at certain milestones — take yourself out to dinner after one week smoke-free, treat yourself to a massage after one month, and so on. Remind yourself of all the good things that go along with being an ex-smoker. And create new rituals for yourself. If you used to smoke a cigarette after meals, take a 20-minute walk instead.

YOU Tools to Quit Smoking

1. Start walking 30 minutes every day — no excuses, every day. Start this on Day 1, one month before quitting.

2. Talk to your doctor about getting prescriptions for buproprion 100-milligram tablets and nicotine patches (21- or 22-milligram patches, if you have a one-pack-a-day habit). Ask your doctor for adjustments if you smoke more than one pack a day. Fill prescriptions.

3. On day 30 (two days before you plan to stop smoking), take one buproprion.

4. Next two days, take one buproprion each morning.

5. On Day 32 (stop day), place one patch on your arm, chest, or thigh (do so daily), in addition to your morning buproprion.

6. On all subsequent days, take one buproprion each morning and evening, and place one new patch on your arm, chest, or thigh.

7. Continue walking 30 to 45 minutes each day; feel free to drink as much coffee or water as you wish.

8. List your daily activities.

9. Phone or e-mail a support person daily to discuss your progress.

10. Begin weight lifting on Day 62. Do not increase your physical activities by more than 10 percent a week.

11. Decrease patch size by one-third every two months until, at six months, you are patch-free.

12. Decrease to one buproprion in the evening after six months, and eliminate that one at 12 months.

13. Carry one buproprion tablet with you at all times to take if you feel a craving.

Excerpted with permission from “YOU: Staying Young: The Owner’s Manual For Extending Your Warranty,” by Michael F. Roizen, M.D. & Mehmet C.Oz, M.D.; Free Press Publishers, copyright 2007.

Drs. Oz and Roizen’s Plan, Tools and Resources to Become an Ex-Smoker