Step Three. Plan On How You Are Going To Quit
The first and most important step that a person can take to quit smoking is to decide to stop.  Being as clear as possible about why you want to quit smoking is very important to how much success you will have in quitting. Decide on a quit date and stick to it.
Set yourself milestones and plan a reward.

Step Four. Get Help and Support From Family, Friends & Your Doctor
You do not have to go it alone.  Ask family, friends and work colleagues for positive encouragement.
Visit your Medical Practitioner, there are lots of smoking cessation aids out there and you just need to find the one that suits you.
 
Step Five. Visualize Yourself as a non smoker:-
In the office while your colleague is stood out in the pouring rain; having a candlelit dinner and not leaving the table to have a cigarette in between courses; sitting all the way through a movie without having to pop out to have a smoke.

The decision to quit smoking is one of the most positive decisions you and only you can make.  In the early days, try to avoid situations where you would normally have a cigarette, for example when out with friends, having a glass of wine, meal times and when feeling stressed because these triggers could set you back on the road to becoming a smoker again.