Not knowing where to start, the first thing I did was review the corporate anti discrimination and sexual harassment. I got lucky where I work and gender identification was included in both anti discrimination and sexual harassment policies. Next thing I took one of my co-workers and tested the waters by coming out to him first. He was a good friend, and it went all right. He wasn't phased by it or anything. So I ultimately asked my manager if I could have a one on one as there is something I need to talk about. So I told her and she was ok with it. She got me in contact with our HR person, who was a big help. So my original plan was to keep quiet among the team, then a reorg happened a year later which threw me onto a much larger team.
I mean this reorg happened out of the blue, literally one day a manager came up and said hi, I am your manager and you now report to me. I was like crap now I got to tell a bigger team. Before I came out to them, I let the new boss know first. I think by telling her up front that gave me some brownie points because she was like "Yea I knew something was up, but honestly I wasn't sure how to approach the subject so I just let it be." Also by doing that I believe it established a trust factor with her. So I wrote this huge letter to our new team explaining my situation and honestly only person truly I was worried that would blow up because he is extremely religious. After I sent it took a few hours for to sink in, but the response was pleasantly surprising everyone was cool with what I was doing except the one guy. Many hours later he approached me and was like we need to talk in private so I was like sure we went to conference across from the security desk and he started going on how religious he was and then starting going for the bible quotes and I simply said, "Don't go there. You have no right to pass judgement on me. That is for me and God to worry about when the time comes. I am not asking you to be my best friend, I am simply asking you to respect me at work as we have no ties outside of work" Then he was like, "Well in that case, I am going to treat you different. I am going to treat you like I treat all the other women here and not ask for your help." I was said, "ummm ok. Thanks.?" That was that with that. He is one of those men that believes that women shouldn't be allowed to work essentially.
My HR person eventually referred me to our Affirmative Action group for the name and changing the gender designation in the records (insurance purposes). They were ok a bit slow but ok to work with and ultimately told me, "If anyone gives you trouble, you call us and we will handle it." The only thing the HR person did not know was I could have been using the female restroom from the get go two years ago according to our Affirmative Action group.
I feel pretty good about the whole thing except for the one co-worker honestly and over time he learned to deal with it and eventually accept it. Even thanked me later when he got promoted because he said, "I changed his way of thinking."