1 - You file the petition in your state of residence (Idaho).
2 - Idaho court website has a name change packet. You should be able to do it without a lawyer.
http://www.courtselfhelp.idaho.gov/name-changes
3 - As for changing the name on her birth certificate you'll have to study up to see if that's even possible:
http://www.floridahealth.gov/certifi...ons/index.html
If that's not possible it should be enough that you keep several certified copies of the Idaho court order in her permanent file and make sure she has a set when she gets older.
Now on to more practical matters.
How old is the child?
What is her first name and why do you want to change it?
What does her father have to say? You will need his consent on the court forms.

