O.,
Ok, so I'm opinionated, but my first suggestion would be to stop offering juice. They don't need it. Second, only offer water and milk from a cup. If he wants the milk, he'll start using a cup. As far as when they should be off the bottle, I always nursed my kids so I don't really know. I think that is a pretty personal thing. No huge medical reason why a bottle would be bad. Now if they are taking it to bed that is a different story (tooth decay potential), but if he is just using it as a cup for his milk at the table or in your arms, I say not a problem unless it is a problem for you. I did have one son who went to daycare and I remember having an especially hard time with getting him to stop drinking out of a bottle, but that was quite a long time ago so my memory is pretty faint. I think he was about 18 months when I finally just put my foot down about it.
As you attempt the transition, remember that he is not a calf and he doesn't really need cows milk. There are other ways to get calcium and Vitamin D, so you might want to look into those if you are concerned about his calcium intake during this time. Just another opinion...I hate milk...hardly ever let my kids drink it...it is made for cows, not people, so it just seems gross to me. A lactation consultant once told me that we should be nursing them until they are 2 and after that no one really needs milk.
Good luck with that. It is so easy to offer advice and so hard to follow through when a baby is screaming!!
D.