When you decide to walk out from a relationship, be firm about your decision and make a move towards it. Definitely this won’t be an easy task. Read out this article that will help you to deal with break up issues and avoid you to be an emotional infant in the process.
No matter how much your partner talk about ‘we had a good time the other day’ etc, just be agree with him/her, but talk about how the good times are few and farther away in frequency. Keep the focus on ‘now’ and ‘I’. Tell properly that how ‘you’ feel differently ‘now’ or how ‘your’ needs have changed in respect to your relationship.
If you think that talking with your partner about breaking it off can lead to counter accusations and situation can escalate into anger, then have a neutral party, for e.g. a friend or a close family member who can bring back the conversation in track. Make sure you do not dent the self-esteem of the other person by picking personality flaws. In the same vein, don’t ever blame his/her parents or inferring friends.
Most important, don’t get angry in the process of communication. It is quite expected that the other person may still feel emotionally attached with you. So your rage will only hurt him /her badly and make the person resort to anger or emotional blackmailing. But don’t waver and go back again as this will only unnecessarily prolong the end and may even make the other person feel like being used in a relationship. Every time your partner wants to talk about why you are breaking up, repeat your stand even at the risk of being crude. Hopefully the next morning your partner begins to see the light.