Quoting RacMarie:" I hate coffee. Maybe just try and wean yourself of the soda slowly. If you start getting a ceffiene headache ... [snip!] ... a ceffiene headache drink just enough for it to go away. Maybe something like that would help and you could eventually stop."
That's what i've done in the past, but it never fails I drink a little and then get hooked again. I even go from one type to another so I don't get stuck drinking it constantly but then I just drink the different kind for a while lol