Renew Indian Passport and Add spouse Surname

I am about to submit an application for my wifes passport renewal.
Her current passport has only Given Name and Black Surname.
I am submitting an application to add my surname to her new passport.

I contacted vfs and they are saying that Name change affidavit , Marriage certificate and my passport copies are needed.

Can somebody help me in understanding how to get the Name change affidavit notarized ? It is asking for " In presence of 2 people " ?