R.L.
It's definitely not too early to wean. At almost 2 I am assuming they are eating solid foods, so this has nothing to do with them being hungry. Also it is definitely not a good idea to put a child to bed with anything other than water or you risk baby bottle rot (tooth decay). So replacing the milk with water is a good idea and maybe adding a snack before bed time will help if they are really hungry.
If they wake up, just put them back down. Eventually they will grow out of that. You just need to be firm about bed time and they need to learn how to soothe themselves. So letting them fuss for a little while before going in to lay them down is good for them.
Other than nap time, do they use a sippy cup? If not start that as well. Just hang in there, they will eventually not need the bottles any longer! If there is anything else, blanket, stuffed animal etc that will help soothe them at night time that may help. Maybe letting them pick something out at the store, and then let them throw their own bottle away so they feel as if they have some control over the decision. You may still have to deal with the waking up for a short period of time but if you hang in there it will pass.
Good luck!