I don't have any great advice, but we are in the midst of switching over from bottles to sippies. Right now, I am doing whole milk in a sippy with breakfast, and doing my darnest to get ds to take it. If he doesn't, I dump the rest in a bottle and give it to him after breakfast. However, just today, ds drank about 5 oz from the sippy, so no bottle this morning! Yeah!
Have you introduced the sippy at all? I started using the Nuby sippy (with a soft silicone spout - which is soft like a bottle nippe) probably about 3 months ago, just with water. It took ds forever to "get" it, but he finally did, and now he's drinking from it himself, holding it and everything. I tried using that same sippy for the milk in the morning, but he didn't want it. So I switched to a different type sippy, and that's the one he started drinking the milk from.
Anyway, my long term plan is to get him to take enough milk from the sippy at breakfast, and drop that bottle completely. Then move on to lunch, then dinner. I figure I need to take my time, and give ds time to adjust, cause he's been on bottles for so long, that it's not really fair of me to expect him to get rid of them overnight or anything!
Good luck!