I myself just decided not to drink it for a month. I had to think it through because it turned out I has a variety of habits that led me to having another glass of Cola, and I had to consciously modify them and keep the goal in mind for the whole time. It is a bit tiring, but you can do it for a month if you really concentrate on it. And then I discovered by the end of the month the craving is practically gone. My habits changed. And then a bit later I discovered I actually don't even like the stuff, so it takes me no effort to keep away from it. I was additionally motivated by rather scary blood test I've got which hinted my health could be in danger very soon if I don't stop, so keeping it in mind was easier.