I found it hard to stop my vices cold turkey, I'm kinda odd so made myself a plan for decreasing my quantity of caffeine, alcohol, processed sugary foods etc. I also gradually increased the decaf content in my coffee to the point that I drink a decaf coffee a week or so. I switched from pop and alcohol to carbonated Water with a dash of juice, to kombutcha tea, then to fun herbal teas cooled and over ice.
I started changing my behaviours as soon as I went to the first information session but got serious about 10 months before surgery (my first intake appointment). I also struggled with the waiting for things to move on the hospital end, but hoped that if they saw the deliberate effort I was making maybe it would speed things up (it hasn't in my case).
I think the awareness and effort on your part is the biggest factor, no matter how small the changes may seem.