Marriage is Over...How to Leave?

Me, F55, Him, M62, married 28 years, no children, lot's of anger issues from him and I am too passive. Should have left years ago, but afraid of the confrontation. It's obvious the marriage is over but I think he stays for convenience. I'm ready to separate and even though we're not "in love" anymore I don't hate him and don't want to hurt him by leaving. I wish he had a girlfriend and I know that's crazy. I don't know how to do this and would appreciate advice.

tl;dr, How to leave my marriage and not hurt him.