I could say that my life is made up largely of habits. So much so that the concept of self control means the ability to maintain my habits. Not so good, but at least my habits aren't harmful, they just tend to keep me from trying new things, changing my life in positive ways, that sort of thing.
I have found that replacement is the most successful, unless there's more to the habit of a hot chocolate at work than the beverage itself. Is there something else you're getting by indulging in the cocoa?
I was in the habit many years ago of having a cup of coffee at a coffee shop after work. It wasn't just the coffee, though, it was being immersed in a scene, feeling a part of something, sometimes seeing people I knew. I was spending too much money on something that wasn't very beneficial to me (the coffee) and the time spent hanging around wasn't all that meaningful, I really wasn't part of the scene, so I stopped stopping by. It was hard, having a cup of coffee at home by myself wasn't the same, and I eventually quit drinking coffee as well. But it awakened me to the idea that a habit can be much more than the simple act, or item consumed.
I find it helpful if you can break it down into all the logical pieces, ie. what it does for you vs. what bothers you about it, then you can better break yourself of a habit.
