Have tried this on a Tiger OS X
- Hold down Apple+S when you hear the chime
- When you see the Aplle on screen, hit the power button once
You should see the text prompt now
- mount -uw /
You should be able to log into the administrator user account with the new password you set now.
You keychain will probably be useless no unless you remember the password for that. I had connectivity issues, the airport would not connect to my wireless networks.
Once I deleted the login keychain, the network issues went away.
To delete the login keychain:
- Open Applications/Utilities/Keychain Access
- Click the Login keychain
- Choose Edit -> Delete