We are running a RHEL 6 server, and for reasons I won't delve into at the moment a few additional accounts were created with UID 0 giving them root access.
I want to get rid of them, but trying to delete the user by username doesn't work as the OS goes by UID and says they are logged in. If I try to log them out all processes owned by root are killed off (ya, learned that the hard way).
I theorize that using usermod might let me change the UID - but I don't know if that will also affect the root account.
Should I just create a dummy account, then edit /etc/passwd to set the UID and group for each account to the UID / group of the dummy account, then remove them all?
What do you suggest that will not result in locking up the server?