How to change my daughters surname

I gave birth with my first daughter last November 2011. I and my ex live in partner were okay during that time. I registered the name of my daughter under his name (my EX). I got pregnant with my second daughter last 2012 and my ex live in partner denied the baby I was carrying. We had misunderstandings that lead to our separations. When I gave birth with my second baby, I registered the name under my family's name. I just wanted to know if it is possible for me to change my eldest daughter to my family's name. I and my ex live in partner were NOT MARRIED at all. My eldest is now 1 year and 8 months old. My daughters were under of my custody and I haven't receive any support for my ex's marital obligations with my kids. What are the process for this matter? I wanted to change my daughters name ASAP or before sending her to school soonest. HELP THERE PLEASE.

I would like for you to read Article 176 of the Family Code. I strongly advice that you seek a Professional Legal Opinion on a lawyer. Because it will take a process requirement for a change of surname.

additional info, Article 376 of the Civil Code. Please read it. If my memory serves me right.

It is not a difficult process.I have attatched a link that tells you the steps for surname change in philippine.

ehow.com/how_6638140_change-surname-under-philippine-law.html