Reset Password

So my dad bought an iMac from my mom, but she does not know the admin password anymore. I read on the apple forums that I should look here for help on resetting the password. The iMac runs OSX 10.6.3. I would really appreciate any help. Thanks

Mac OS X 10.6: If you forget your administrator password

Ah, yes. I forgot to mention that sadly we do not have the installation disks.

Then you should try to get the media somewhere.

You can also try this method:
https://discussions.apple.com/docs/DOC-5381