How do you break up with someone?

“I’m 26 and I’ve never broken up with someone before and I don’t know how to do it. I don’t want to be rude, however I feel it would be awkward to sit through a dinner and tell him at the end or text ‘we need to talk’ and specifically meet up just to break up. We’ve been together for a year and I’ve already put it off for a month because I’m scared. What advice do you have?”