Changing Gender marker on Drivers License/ID can be done at any DMV, ID Centers by filling out https://www.dol.wa.gov/forms/520043.pdf - Change of Gender Designation Form
To change your sex designation on your birth certificate (and in turn most other places), follow the steps listed below. Remember, that if you choose to legally change your sex designation, there is a chance of having troubles with insurance or getting the selective service to leave you alone in the future.
The 422-143-Request to Change Sex Designation on a Birth Certificate for an Adult form must be completed to request the birth certificate change
Make sure that it is signed in the presence of a Notary Public (these are at UPS offices)
If your full current legal name is different from what's on your birth certificate, provide a certified copy of the court order. If you want your name amended on your birth certificate, check the appropriate box on the form (they might ask for more documentation then).
Once your birth certificate sex designation change goes through, make sure you change ALL appropriate legal accounts and documents (you might need a certified copy for each of these). Remember: to change your birth certificate you have to follow the laws of where you were born/where your original birth certificate was issued, so laws may vary from WA laws. Here is a checklist to make sure you don’t have any trouble down the line: (https://transequality.org/sites/default/files/docs/resources/ID-Documents-Overview.pdf)