Q: How do I recover a system administrator password

Resetting or changing a password:

For Snow Leopard or earlier:  http://support.apple.com/kb/HT1274

If it's running Mac OS X 10.6.8 or earlier, insert a Mac OS X install DVD, restart with the Option key held down, click on it, and use the Reset Password utility.

The icon of the DVD on your desktop.

The icon of the DVD on your desktop.

Boot into single user mode and reset it that way:

http://osxdaily.com/2011/04/25/change-admin-password-mac/