I have had it changed, this is how I was able to legally marry my Wife.
It actually was a lot less difficult than I anticipated; I felt I had to jump through far more hoops to get my hysto done.
I downloaded the forms from my state’s Births, Deaths and Marriages website and had my GP who has been treating me for 8 years fill it out, alongside my Surgeon who performed my Hysto. I also attached a very large stack of documents pertaining to my chest surgery, psychiatrist letters for approval of prior surgeries and diagnosis etc and had them witnessed and signed by a Justice of the Peace for offical measure. I did not have to enclose these as per the guidelines on the BDM website, but I was very paranoid about spending so much time and money in order to get this changed I wanted to do every thing I could to ensure it would be processed smoothly.
Lo and behold, about four weeks later I recieved a brand new birth certificate, with no mention of prior name or sex. Lovely.