I am writing to inform you of changes that I am in the process of making. I am transgender, and have begun the process of changing my appearance to match that of my male gender identity. I will not be changing my name, but I will no longer be a "girl George". As I become more masculine, you may continue to see changes in my appearance and self-presentation, but please be assured that I am still just me.
It is customary in the English language to refer to men with the gendered pronouns "he", "him", or "his". I also ask that you start using male pronouns when referring to me, both in person and in writing, email, etc.. I recognize that this may be difficult at first, and I will not be offended by genuine mistakes if made without malice. However, this change is necessary to avoid confusion for clients, new coworkers, and others. I am aware that some of you may not understand or approve of this change, but I request that you continue to treat me with human dignity as I do you.
I will be out of the office until returning on [end leave date] and upon my return I intend to present fully as male. That will be the "official date" of transition here at the office, and I am in the process of changing all my legal documents to reflect this information. I expect that some of you may have questions. If you do, please do not hesitate to talk to me. There are some personal questions I may not answer, but questions about this process are definitely open for discussion with me directly. You may instead choose to discuss this with [director's name]
… or, like my wife says, "go ask your Google."