How to reset your Mac OS X password without an installer disc

8:37 AM Duminda Malshan
  1. Power on or restart your Mac.
  2. At the chime hold down Command+S on your keyboard to enter single-user mode.
  3. This step is optional, but it’s a good idea because it checks the consistency of the hard disk before moving on. At the prompt, type fsck -fy and press Enter/Return. Wait for the checks to complete before going to the next step.
  4. Type mount -uw / and press Enter.
  5.  Type launchctl load /System/Library/LaunchDaemons/com.apple.DirectoryServices.plist and press Enter.
  6. Type ls /Users and press Enter. This lists all of the usernames on the computer – helpful if you don’t know or remember what these are.
  7. Type dscl . -passwd /Users/username password and replace “username” with one of the users displayed in the previous step. Replace “password” with a new password of your choice. Press Enter.
  8. Type reboot and press Enter.