Mass change of samba user names

[Scarry, Robert]

I am a new administrator at a site which uses samba, I would like to do a
mass change on samba user names.  The user naming convention is changing and
I would like to create a shell script that will do a 4Loop and use awk to
change all names without re-creating every user.  

I have already tried to change the name directly from the smbpasswd file, it
does not work.  

Any thoughts?