Name Change If Legally Separated But Not Divorced Yet

Does anyone know a law or procedure about changing your name if your not yet divorced? I am legally separated with a daughter that was from a previous relationship. Myself and my daughter had our names changed after I got married. Now that I am separated and going throught the divorce I would like to change our names back. Can this be done if you are not divorced? Or is the legal separation good enough to change our names? Thanks for your answers.