How do i break up with my boyfriend?

Weve been dating for two weeks and before we talked for about 3 weeks. At the beginning it was alright (2-3 days) and then i just wasnt feeling the relationship anymore and i was like "ill give it some time" well i gave it some time, and its not working. What do i say to him? I dont feel attracted to him and I feel like we don't really click. Thanks!