So, obviously getting rid of bad habits is the first step towards developing good habits. Develop the right mindset. Think about the enormous benefits one obtains by eliminating bad habits. And starting a good habit! Strive hard towards retaining the good habits. One might falter. But do not worry. Try again. And again. Until the good habit is ingrained in one's system.
Once one is successful in kicking an old, bad habit, one can utilize that experience in helping out others. Think about this aspect too when you are trying to start a good habit. The satisfaction one obtains from helping others is really priceless! Of course, kicking a bad habit is easier said than done! But give it a try nonetheless.