Changing step daughters name once married?

[Scania]

I'm getting married at the end of March, my 6 year old step daughter wants the same surname as her mum will have once were married.

Her natural father lives out of the country, has little - if any - contact with her, and we don't foresee him having any objection.
Basically, I'm wondering how I go about doing this.

Anybody done this before? Any pointers / pitfalls appreciated.

 

[Scania]

He does not have parental responsibility, he lives abroad, pays no maintenance & my partner has a document from her solicitor confirming she has sole responsibility.