How the hell do you bring up the conversation?

I'm 22, male, gay and am out to most of the people in my life that matter. The only person that doesn't is my dad.I love my dad, but he is conservative, and Christian, and, from what I have been able to figure out over the last few days, not as homophobic as I thought. I have no idea if he still does but he used to believe the "Gay agenda" crap was real. I can't quite tell if he does.The thing is, I made a new years resolution that I haven't told anyone about. I resolved to become a happier person, to love myself, and to not hide myself. So I want to tell my dad, and I want to tell him before I head to Europe for 5 months, so I can be open about what I'm doing and I don't have to hide anything on facebook or the like.I think he'll be fine with it. He's very libertarian when it comes to other people and has expressed before that he wants the best for me, and knows that I need my space to discover life on my own (I'm a middle child, it's very important lol).So here's my dilemma: how do I bring it up? How do I bring up how I feel and be open with him?