I want to open my old iBook G4 Apple computer.

Option 'change admin Password' becomes available on startup w/ installer disc.

• Reset a Lost Password in Mac OS X with a Boot Disk | osxdaily

https://osxdaily.com/2010/02/21/reset-a-lost-password-in-mac-os-x/

One has to have a dvd or cd ~ and start up from that disc. That

usually has to match an older Mac system running in computer.

(Helps if you kept original or later Apple upgrade system media.)

• How to Reset Your Computer Password If You Lock Yourself Out | helpdeskgeek (see OS X)

https://helpdeskgeek.com/how-to/how-to-reset-your-computer-password-if-you-lock-yourself-out/

• Reset Root or admin password on Mac OS X - Hawkdive

https://www.hawkdive.com/reset-apple-mac-os-x-root-or-admin/

Various older instructions also have suggestions on how to reset password without

the installer startup disc media. Generally uses a shortcut, command-line or terminal.

Some of those ideas mentioned, can be tricky; between two that follow. One more

than often would work without the installer disc, & without the built-in utilities, etc.

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

http://www.macyourself.com/2009/08/03/how-to-reset-your-mac-os-x-password-without-an-installer-disc/

Two methods ^ are shown. "A third method of resetting your Mac’s password

requires some additional explanation. Rather than simply changing the pass-

word like the previous two methods do.. This one fools the operating system

into believing it has never been started before. ~This means when you restart

the machine, it will take you through the entire setup & registration process

all over again." (could be done offline; may not require apple authentication.)

• Reset Mac OS X User Password Without CD - with command line | brakertech

https://brakertech.com/reset-mac-os-x-admin-user-password-without-cd-disk/

"Reboot your mac

When you hear the chime, Hold apple + s (this puts you in single user mode)

Upon reaching the terminal prompt input the following: [see site detail]

This would use 'Single User' mode, input simple command; as shown, & restart.

If still trying to use the 'without disc method' ~ you may try earlier option again.

[The path from here has been forgotten, however unless you mistakenly erase hard

drive by using Disk Utility (out of turn, not needed to reset password) you are in a

better place to learn ~ from older OS X; information is online, to complete mission.]

Sueshe Said:

"I’ve forgotten my password as it’s been years since I opened it?"

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See if this works: Change or Reset the Password of a macOS User Account in macOS Mojave or Earlier - Apple Support. It is a much older device, so it is at question.

Recalling the Password:

Think of an old password. Think of a place you may have stored it in. Think of a keyword that makes the password come to mind (i.e. Pat, Family Member, Best Friend, Teacher, Place of Birth, etc). Maybe it is simply: password or admin.