You may run across an issue when changing your AHV password to a previously set password. While it's not best practice, there may be a edge case where you need to reconfigure that same password.

[admin@linux ~]$ passwd
Changing password for user admin.
Changing password for admin.
(current) UNIX password:currentpw
New password:newpw
Retype new password:newpw
Password has been already used. Choose another.
passwd: Authentication token manipulation error

To work around this, you can remove the password history from the opasswd file.

Use your preferred text editor to find root and delete the corresponding entries for the user in: