Breakups

We live together but I just don't love him anymore.  He's the only guy I've ever been with, and it's been 3.5 years. I legitimately don't know how I'm going to break up with him though. I have to be able to safely get my things out of our apartment so I don't know if it's better the get my things while he's gone and be waiting when he gets home and then tell him what's going on or tell him the night before and get my things the next day.  I don't think he's going to be violent but I expect lots of crying and begging me to stay. I just don't know what to do and my friends have been no help.