It's an inexpensive process, around $150, and you don't need an attorney. The Court Clerk in your County likely has the forms that you need and should be able to help you. Your mother will need to be on board with the idea and file the papers on your behalf. In your petition you would normally need to include:
• The name and address of the petitioner; how long the petitioner has lived at the given address.
• The date and place of birth of the petitioner; the birth certificate number, and place of registration, if the birth is registered.
• The name desired by petitioner.
• A clear explanation of why you want the name changed.
• A positive statement that the change is not sought for any illegal or fraudulent purpose, or to delay or hinder creditors.
The answer given does not imply that an attorney-client relationship has been established and your best course of action is to have legal representation in this matter.