I was able to change my school records and diploma. Try googling your school name and the words "name change" or "gender change". For my school, the name change form allowed me to change my gender at the same time. I also had to fill out a separate form to get a diploma with my new name on it. If the school website does not have a page for name and gender changes, you can try calling the school's registrar's office and asking how to proceed.
Edit: Also, I just had to provide a copy of my driver's license and the official court order for my name change.