Change of surname

Hi,

What is the procedures for me to change my daughter surname to my current husband surname?  The situations is like this, i have a daughter which is 6 years old now with my ex boyfriend, and his name also stated on her birth certificate. I've saperated with him since 2009. I have been married recently and me and my husband would like to change her surname to my current husband surname. Please advise.

Thank you.