Total Change of First Name

Hi everyone who's knowledgeable about the law. I just wanna ask on how can I just change my first name. I've searched it online but I still can't fully comprehend it. Okay, here's my situation. I'm 19, graduated few months ago and just recently decided to transition as a woman. But a slow transition. Even my parents are yet to know about this huge step I'm taking. I have yet to dress as a woman or anything of sort. I'm just starting to let my hair grow out. So, basically no one yet knows me by my "new name" that I choose  aside from my 30 facebook friends on my new account. I have two first name, I would like to keep the  second one but not the other, and probably add another. So basically, like this:

Example of my name now:: Mark Kieth Dela Cruz.
Could be "new" name::  Stefani Kieth Mae Dela Cruz.

How can I make this a reality? What's the process? Fees?

I'm sorry if I'm asking too many questions, I just want answers. I'm also too afraid to go to a lawyer in fear of being judge and discriminated just now. Hope to hear from anyone of you. Thanks.    

if you were born biologically a male, sadly, there is no legal remedy to change that to female under current law.

attyLLL wrote:if you were born biologically a male, sadly, there is no legal remedy to change that to female under current law.

I'm not trying to change my gender on papers. Just my name.

Here are the grounds for change of name: Rule 103 (CHANGE OF NAME) using valid and meritorious grounds including (a) when the name is ridiculous, dishonorable or extremely difficult to write or pronounce; (b) when the change results as a legal consequence such as legitimation; (c) when the change will avoid confusion; (d) when one has continuously used and been known since childhood by a Filipino name, and was unaware of alien parentage; (e) a sincere desire to adopt a Filipino name to erase signs of former alienage, all in good faith and without prejudicing anybody; and (f) when the surname causes embarrassment and there is no showing that the desired change of name was for a fraudulent purpose or that the change of name would prejudice public interest.