Do you have an AO3 page yet? If so, posting is really easy. There's a button that just says post or new or something. It wasn't hard setting it up if you haven't, but it's been so long since I did it, I don't remember what I had to do. I remember moving all my stories over by hand back in the day. I think at the time it took me a very long day, but it wasn't hard. I just had to go back and make tags for everything