So you’ve found someone to buy your old Mac, and now you’ve got to clear off your data.
Here’s how I prep my Macs for sale in less than 5 minutes. No Recovery Partition necessary.
Open System Preferences and Create a New Administrator User
The first step is to create a new user with Administrator rates.
Open System Preferences. Click on Users. Unlock to allow changes. Hit the + button to create a new user with Administrator rights.
Log Out and Switch to Your New User
The next step is to delete your old user account.
Log out. Log in to your new administrator user.
Open System Preferences and Delete Your Old Account
Open System Preferences. Click on Users. Select your old account, and click the minus button.
I’m assuming you already have a backup, so click on Delete the home folder, and check the Erase home folder securely.
Important: You are securely erasing your account. If you do not have a backup, you will lose everything. You do keep backups, right? Go double check it before deleting your account.
Bonus Step: Securely Erase Empty Hard Drive Space
Open Disk Utility. Select your Macintosh HD partition. Select the Erase tab. Click Erase Free Space. You can choose from 3 options ranging from Fastest to Most Secure.
Congratulations, Your Computer is Ready
After completing this walkthrough, you have a fresh user with the default settings, and you have securely wiped your personal data.