Supposedly in Oregon you use the same form that you use for name change, except that you cross out 'name' and add 'gender'. But you do need a surgeons letter stating that it is irreversible. I don't know if a letter stating that you had an Orchi would work or not. When I go in on September 4 for my name change, I am going to take my carry letter and see if the judge is in a good mood or not.

When I changed my license, I had a letter from my therapist and they changed the name and gender marker. I am glad I did it when I did, because they changed the law the following week and you now need a birth certificate or other proof you are in America legally.
So I will be me even without SRS.

Janet