Although I breastfed my daughter for 12 months, I cut out night feeds when she was 8 months. The health visitor advised me how to go about it, I went to a great breastfeeding group where lots of helpful advise was given, any in your area?
I was told to slowly cut down on the amount of time dd was on the boob, 5 minutes less each night until she was barely on there at all. If she fell asleep whilst feeding I had to wake her up before putting her back in her cot, this was to stop her associating feeding with falling to sleep. They need to learn to get themselves to sleep, that way when they wake in the night they can settle themselves and not need comfort feeding back to sleep.
I then had to do controlled crying. The health visitor can also advise you on this. It's pretty awful at the time, you have to be ready and really want to do it as the worst thing is to give up half way through, but if you're anything like me you'll be in tears feeling really upset about leaving her . Having said that it worked and my daughter has slept solid, (unless poorly) from 7pm - 6:30am every night since, and she's 3 now. Also worked on her younger brother.
This is how it works. If dd wakes go into room, do not turn on light, do not talk, do not lift her out of cot. Stroke her head softly and say something soothing, 'sleepy time, shh shh' or something similar. Do this until dd stops crying then leave the room. When she starts crying again leave her for 5 minutes then go back in and repeat. Next time leave it 10 minutes before going in, then 15, the maximum you should do is 20 minutes in between going in to soothe her. Eventually dd should get the idea that she's not getting the boob, interaction, cuddles etc, so might as well go to sleep. I had to do this every night for a week with my daughter, but worked in 2 nights for my son.
Like I said it is horrid and I know a lot of Mums can't go through it, but it does work and you will eventually have a happier baby who sleeps well and a happier less tired Mummy. I would advise speaking to a health visitor about it though.
Good luck however you decide to tackle it! xx