This will open a pop-up menu, choose Mac OS Extended(Journaled) or APFS, enter a name, then click Erase.Select your drive’s name from the left side list and click the Erase.

If there is an internal hard disk, wipe them too.

The next is to use Disk Utility to completely erase your startup disk.

Release the keys when you see the Apple logo, and until the macOS Utilities window appears.

Then restart it by holding the Option+Command + R keys.

How to reset MacBook Pro or Air if you are selling The second situation is where you are doing a reset to start fresh i.e. The first situation is when you are planning to sell your MacBook to someone else. You might have to download OS and App updates. After the reset, you can always get back to the same state as you were before you reset MacBook to brand new. It is recommended that you backup all your data using the inbuilt backup system, Time Machine, to an external drive.

Though, I would warn you that when you hard reset MacBook Pro or Air to factory settings (without disc), it will wipe clean everything. While MacBook is one of the finest machines that usually don’t get hiccups, but if you ever had to hard reset your MacBook Pro or Air running OSX, it’s easy.

Wipe macbook air to sell