how to reset mac password using diskutility

In this tab, choose '1 Partition' from the drop-down menu, and then give the partition a name, set it to be 'Mac OS Extended (Journaled),' and apply the changes. In Disk Utility, select your internal hard drive (listed above any volume names contained on it), and you should see a 'Partition' tab appear. Then after selecting your language choose Disk Utility from the Utilities menu.

To reinstall the original version of OS X if your Mac came with a gray installation and restoration DVD, insert this into the optical drive and reboot with the C key held down. Reinstalling the original version of OS X will allow the new owners to choose what version they would like to install. While you can install the latest version of OS X that you purchased from the App Store, technically this is a copy licensed to you, not the new owners. The next step is to format your system and reinstall the original operating system software that came with it. Granted, RAM and hard drive upgrades may be difficult or unnecessary to undo, but if you have a Mac Pro with PCI express cards installed, then unless you are selling them together as a package, consider removing them from the system. If you have added any upgrades or expansions to the system, then you might consider removing them. If the Mac you are parting with is one of these systems, then first disable this authorization. For example, if you play your iTunes music on additional computers, you will need to authorize them to play any DRM-protected iTunes content. Next be sure to disable any services that are associated with your system, as some are machine-specific and require authorization of a limited number of machines to work. Either method should result in a full copy of your computer which you can restore or migrate to a new system, if needed. You can do this using Time Machine, or with a system cloning tool. The first step in any factory reset of the system is to completely back it up.

Of course you might consider removing your user account from the system, and setting up a new administrative account for the new users, but the easiest and most thorough way is to fully format your system and reinstall OS X. If you are selling or donating your old Mac, then you might want to factory reset the system not only to provide the new users with a fresh start, but also to ensure your data is secured from the new owners.

How to reset mac password using diskutility