Habits are formed overtime. And like a cement block that has hardened in the mold, it really is hard to break. 

   More often than not, people get used to bad habits than the good ones. So, to break free from negative habits, one should form new positive ones to replace the old ones; practise it for a long time till one gets used to it. Form new habits, and in no time, the old ones will become less distinct, and slowly fall out of use.