How should i get Divorce from my Wife ?

Hi..I am Ajay and I got married in 2008.Since starting of my marriage we were going through lot of ups and down as my wife was not at all family person and after my dad's death i was the only one to look at my sisters and My mother.My both the sisters are married an well settled. So finally three years ago one day when she misbehaved with my mother, we fighted a lot and now from last three years i am not in physical relation with my wife and i doesn't want to stay with her anymore. Now whenever i start talking he regarding this she usually starts doing drama or ignore it. I have told her several times that we cannot stay together now and we have to get seprate. Now best thing about this marriage was our 3 years daughter, I want to keep her with me as i know she is not even characterly Good. She comes with the background where her mother has married twice and is not even bothered about her second Husband, as in where he has gone. I want to get separate now but want to keep daughter with me...but she refuses everytime as she aware she is the heart of evryone in family and we gets quit everytime we talk about Divorce, as she then says...ill take her along.....Now u people please guide me wat to do and how in best possible manner and quietly as i dont wanmt problem for myself and even for her...after seeing nobody in there family is bothered about each other.