Alyssa makes some good points.
I would agree with her pretty much 100%.
When I came out to my church, I had talked to the priest about it, we decided to do an announcement, and I got up and read a little something I had prepared. It was about 5 minutes long, said I had GID, was getting help, etc. Thank everyone for their support and prayers, that kind of thing.
If the church you're going to isn't full of people who know you well, then you might be able to just get away with being Kody. If you're going to be running into people who knew you as a kid, then you might consider at least giving heads-up to certain people (as Kate suggested).
One of the most important things is to be comfortable. If you don't want to out yourself to a bunch of people, then just say that you're Kody, and that's that. If you're okay telling a few people, then do that. But don't feel like you have to out yourself to every single person you meet. They can relate to you perfectly well without knowing every detail of your life.
Be comfortable, and be yourself. These things can be tough, but they do have the tendency to work themselves out, sometimes better than one might expect. Good luck!