I used a lawyer. I began the process shortly before I planned on going full time. That was a mistake in my case. It took a long time to be finalized. I ended up living full time for quite a while hoping to not get carded for anything or getting pulled over while driving. If it's possible where you live, you may be able to petition for a sealed case. That would mean no reporting in newspapers and the only people in the courtroom would be you, your lawyer, and the judge and it wouldn't be printed in the records. If you're able to do this, you'll need to prove that there is probable danger to yourself. This is easy considering the amount of violence and murder to trans women, unfortunately. I didn't need a letter but my lawyer suggested one just in case there was a question on whether your actually trans regarding your petition for a sealed case. It took me well over 6 months to get my cetificate. Yours may or may not be faster and in hind sight I would have much rather spent less time hoping to not be carded with my new name presenting as male rather than longer the other way around. Kinda up to you and a little luck I think.