I was asked to reset the passwords on an old Mac. This is usually done by booting with an install disk for the right version of the operating system.
Determine OS Version
The OS version was not displayed on the screen. To determine this, I booted to single user mode. (Hold down Apple-S while booting.)
From the command line, type:
This will show the OS version. For this machine, it was OS X 10.4, or Tiger. I do not have a working install disk for Tiger, so I could not do it the easy way.
After booting into single-user mode again, I had to mount the root directory as read/write, then start the base services.
# mount -uw / # sh /etc/rc
I didn’t t know the short name for the account, but that was easily determined by
# ls /Users
Now I could do a simple
# passwd account # reboot