Being dumped is excruciating, but being the person who ends the relationship is terribly difficult as well. If your boyfriend is a big jerk, giving him the boot shouldn't be too hard. However, if he is a sweet, kind, good guy and you are just not that into him, telling him it's over is tough. You know the relationship is not going to go anywhere, but you really don't want to hurt him. A painless breakup may be impossible, but you can still let him down gently.
Choose a day to dump your boyfriend. Make sure it is a completely insignificant date. Don't add insult to injury by breaking up with him on his birthday, Valentine's Day or the anniversary of the day his dog died.
Keep your distance for at least a week prior to the date you have set. Don't call, message or visit your boyfriend during this time. If he calls you or stops by, tell him you are busy. This gives you time to consider what to say and to be certain you really want to go through with it. Your boyfriend is also likely to sense that something is up, and will (hopefully) start to prepare himself emotionally.
Meet at a place where you are both comfortable, but one that is not too crowded with people. You don't want him to feel embarrassed or humiliated if he gets choked up or teary. Make sure it is someplace you will be able to leave quickly and easily, just in case he starts to make a scene or things become heated.
Be honest with your boyfriend about your reasons for wanting to break up. Get right to the point. At the same time, be sensitive and choose your words carefully. It's a good idea to rehearse what you are going to say several times before you meet. Have the conversation while looking in a mirror, or ask a good friend to role-play with you.
Meet the questions your boyfriend will likely have with genuine answers and tactful words. When stating your reasons for breaking up, start your sentences with "I" instead of placing blame. For example, instead of saying "You don't make me happy," you might say, "I'm not happy."
Wish him the best. Tell him that you truly hope he finds someone who will love him the way he deserves to be loved--then reiterate that it's just not you. Don't say anything that might give him false hope, such as "I'll always care for you" or "I'll still be here if you need someone to talk to." As much as you may hurt for him, the best thing you can do now is walk away and allow him to work through his pain.