Okay i have just been through myself (thanks for the heads up HOTI), what i did was cut the amount of milk down in the bottle to start with, she didn't even notice that she was getting all water and a dribble of milk for colour. I know she was still getting the bottle but it sort of gave me the confidence to know that i was 'winning'...lol

Then (and this is the hard part) i only gave her a bottle first up in the morning and then before sleep/s. She threw HUGE tantrums about it and it was horrible to watch but i just kept her distracted (which i know is harder with a new baby) and offered food or kept giving her a bottle of plain water to drink. I worked out that it was really only a habit and a comfort thing as she was not really that thirsty once she only got given water to drink.
The thing about giving her the water in a different bottle (and we tried about 5 until we got one she liked) is that she started to think of that one as her daytime bottle and the milk one was only for set times.

She was and still is sometimes a terrible sleeper but i was finding because she was only drinking milk she was either a) waking up frequently because she was hungry or b) waking up because she had a wet nappy.

I don't know if any of this info helps at all but i know i was at the end of my teather with the constant demands for milk, no sleep, constipation from drinking so much milk that i knew i had to try and do the tough love approach. That worked for me and yes i had to leave the room occassionally to cry because i felt so bad when she was upset and it would have been easier to just give her the milk but i knew that her behaviour was starting to effect the whole family unit. Good luck, stay strong...my little one eats like a horse now