weaning baby off bottle/nighttime feedings

My son is going on 9 months & still wakes up every 3-4 hrs to eat & I was being told that by 6 months u should introduce asippy cup to begin weaning them off the bottle & night time feedings. We've been putting water in his Dr.Browns sippy cup which he loves, just sometimes the flow is really fast for him I think. Any suggestions on how to wean him off the bottle & remaining asleep for the night. Hes on solids, cereal, can stand up for quite sometime & is already crawling. No rush if it's no big deal but like I said we were recommended to introduce the sippy cup to get him off the bottle esp since it can cause rotting teeth (milk) I mean. Thanks!