Why change names? If a story is true then why hide facts. If a person is embarrassed into giving details then why write an auto-biography.
However if you are writing a work of fiction based on real events then there is no problem.
My good friend has willed me all his diaries dating back 60 years and within the pages are the low down on the real criminals of London, famous UK villians and even more famous celebrities that lived on the edge, murders, wrongful convictions, bent top coppers and all.
He has written in his diary without fail every day in those 60 or more years and although he has related some great tales to me, that could be a book in itself, it is within the diaries that the real stories lie.
When the time comes all will be revealed including real names but as he is only 76 at the moment it could be a few years yet before I seek a publisher. Unless of course I go first.
Willy