Follow these instructions step by step to prepare a Mac for sale:
Step One - Back up your data:
A. If you have any Virtual PCs shut them down. They cannot be in their "fast saved" state. They must be shut down from inside Windows.
B. Clone to an external drive using using Carbon Copy Cloner.
1. Open Carbon Copy Cloner.
2. Select the Source volume from the Select a source drop down menu on the left side.
3. Select the Destination volume from the Select a destination drop down menu on the right
4. Click on the Clone button. If you are prompted about creating a clone of the Recovery HD be
sure to opt for that.
Destination means a freshly erased external backup drive. Source means the internal
Step Two - Prepare the machine for the new buyer:
1. De-authorize the computer in iTunes! De-authorize both iTunes and Audible accounts.
2, Remove any Open Firmware passwords or Firmware passwords.
3. Turn the brightness full up and volume nearly so.
4. Turn off File Vault, if enabled.
5. Disable iCloud, if enabled: See What to do with iCloud before selling your computer.
Step Three - Install a fresh OS:
A. Snow Leopard and earlier versions of OS X
1. Insert the original OS X install CD/DVD that came with your computer.
2. Restart the computer while holding down the C key to boot from the CD/DVD.
3. Select Disk Utility from the Utilities menu; repartition and reformat the internal hard drive.
Optionally, click on the Security button and set the Zero Data option to one-pass.
4. Install OS X.
5. Upon completion DO NOT restart the computer.
6. Shutdown the computer.
B. Lion and Mountain Lion (if pre-installed on the computer at purchase*)
Note: You will need an active Internet connection. I suggest using Ethernet if possible because
it is three times faster than wireless.
1. Restart the computer while holding down the COMMAND and R keys until the Mac OS X
Utilities window appears.
2. Select Disk Utility from the Mac OS X Utilities window and click on the Continue button.
3. After DU loads select your startup volume (usually Macintosh HD) from the left side list. Click
on the Erase tab in the DU main window.
4. Set the format type to Mac OS Extended (Journaled.) Optionally, click on the Security button
and set the Zero Data option to one-pass.
5. Click on the Erase button and wait until the process has completed.
6. Quit DU and return to the Mac OS X Utilities window.
7. Select Reinstall Lion/Mountain Lion and click on the Install button.
8. Upon completion shutdown the computer.
*If your computer came with Lion or Mountain Lion pre-installed then you are entitled to transfer your license once. If you purchased Lion or Mountain Lion from the App Store then you cannot transfer your license to another party. In the case of the latter you should install the original version of OS X that came with your computer. You need to repartition the hard drive as well as reformat it; this will assure that the Recovery HD partition is removed. See Step Three above. You may verify these requirements by reviewing your OS X Software License.
You can reinstall Snow Leopard if it came with your computer. There is no physical media for Lion or Mountain Lion and there never has been.
To reinstall Snow Leopard will require that you first erase the hard drive. You cannot install Snow Leopard on a drive that already contains Lion or Mountain Lion. See below:
Downgrade Lion/Mountain Lion to Snow Leopard
1. Boot from your Snow Leopard Installer Disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Utilities menu.
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, set the partition scheme to GUID then click on the OK button. Click on the Partition button and wait until the process has completed.
4. Quit DU and return to the installer. Install Snow Leopard.
This will erase the whole drive so be sure to backup your files if you don't have a backup already. If you have performed a TM backup using Lion be aware that you cannot restore from that backup in Snow Leopard (see below.) I suggest you make a separate backup using Carbon Copy Cloner 3.4.1.
I'm not sure what I should be looking at. On the left is an open Finder window for an installer DVD. On the right is a Disk Utility window that doesn't really tell me much.
To install Snow Leopard you need to boot from that installer DVD:
Booting From An OS X Installer Disc
1. Insert OS X Installer Disc into the optical drive.
2. Restart the computer.
3. Immediately after the chime press and hold down the "C" key.
4. Release the key when the spinning gear below the dark gray Apple logo
5. Wait for installer to finish loading.