How do you break up with your boyfriend?

Well, the title of the question speaks for itself, but really all I wanted was some suggestions on how exactly to bring the topic of breaking up with my boyfriend. Should I ask him outside, tell him we need to talk and all that, or do something else?
Even though I am 21+, this is my first break-up, and he was my first boyfriend, so any help is appreciated. ┗( T﹏T )┛
Just to clarify, the break-up is due to me having stopped seing him in romantic light since some time ago. We have been going out for almost 2 years...