Habits are little chunks of auto-pilot behavior that get burned permanently into your mind. Once you develop a habit, you can never really delete it.

Habits start with a trigger, which sets off your automatic behavior. They end at a pleasant reward that reinforces your habit.

Describe your own behavior in detail, and search for clues you might have missed before. Find your trigger.
If you have a habit of making coffee, it might be triggered by entering the kitchen. Some people eat in response to boredom or buy stuff in response to their desires.

Try to make a new reward that is similar to the old reward.
If it is a coffee habit, the reward is a warm beverage and an excuse to sit still and reflect. For that reason, a substitute like herbal tea would work.

Reinforce habits with belief and community.
When we tell stories of our own lives of making the desired change, it creates belief. When others chime in, it shows that achieving changes is possible for everyone.