How to end a relationship?

I've been thinking about ending my 1-year relationship for a few weeks. Then, last night when I was making dinner plans with my BF, he said it would be a good opportunity for us to have a chat about our relationship and where it was heading. He said that it would probably be a difficult, uncomfortable conversation. So now I'm thinking that he's planning on breaking up with me!

I think that the relationship has just run its course but at the same time, I would prefer to be the one ending it, rather than the other way around. What should I do?