Chosen Solution
I just bought a used iBook and it has a password for the admin account. I do not have the OS reinstall disks. How can I remove the password?
I was able create a new admin account by pressing command-s at startup, and then following instructions I found online. Then I deleted the other admin account. Works great now!
Without an original system installation disk or a retail system disk you can’t remove the password. Try a simple press of the return key and see if it works. Also according to cryptologists 1/3 of all passwords are “password”.
Get solution from this official blog of mac password.