I arranged a causal meeting the the board president where I work. I explained what was going on with me. At the time I had polish on and woman's leans as well as my bra. I just explained straight forward and honestly where I'm at in my life. She commented that she had thought I had Gyno but didn't think it fit with all the weight lose. She was 110% please and happy about my changes and had really noticed the mood and attitude changes but really had no way of bringing it up with me. So in a way it opened her door as well.
She was courteous and didn't ask any of those questions you don't ask, she did ask if she had permission to talk to the rest of the board on my behalf and I agreed.
I let her know I would be fazing in changes over a couple weeks with cloths and make up and hair etc and all she ask was a heads up so she knew how to deal with any queries from resident in the building.
Spent a week changing over and 10 days later Donna was full time fully dressed and happily out at work. There has not been a single issue building wise except one contractor I deal with that has an issue with transphobia. Oh well his lose as he is no longer on the preferred vendor list. He must have thought the board wouldn't let me terminate his services or how much backing I had.
You need to be open and honest with the people around you, there may be confusion and looks and strange comment but you have to realize people need to learn the difference as well.
I had one older couple ask if I was cross dressing or in drag, I educated them and now they have learned something new as well.
Best wishes and good luck and enjoy the journey.