I believe your actually asking about changing the LNAB (Last name at birth). You can read below about this.
You have to be the profile manager to change the last name at birth. Once that is the case, there is a small [EDIT] sign next to the last name at birth. You select that and you'll be on your way!
And I'm sure I don't need to mention this but Please provide a source for your change along with a reason for your edit. If you have any uncertainty of the LNAB it should be changed to Unknown instead of another name.