In Scotland, any man or woman is free to change his or her name if they want to. You can make this change official and your birth certificate will show both your old and new names. If you are over the age of 16 you don't need parental permission, but if you are under 16 you do, in which case, a parent or guardian must make the application for you.
You can get an application form in any registrar's office in Scotland. Completed applications should be sent to the National Records of Scotland:
National Records of Scotland
Change of Name Unit
General Register Office
New Register House
You should also send £40.00 for recording the change of name plus £15 for a new birth certificate. If more than one person in the same family is applying for a change of name, at the same time, then each subsequent application is £10.00.