One of the most common tasks you’ll ever do: Resetting users’ passwords.
First, make sure the user doesn’t have Caps Lock on. Also have them try at least three times: often you’ll get, “Hey, it worked this time!”
Or, they may have forgotten their password. Or, it may have expired.
Use:
passwd <user name>
to reset the password to something easy. Then issue:
chage –M 30 –d 0 <user name>
to force the user to choose a new password upon their next login.