[Solution] How To Reset MacBook Air To Factory Settings

1. Sign out of iTunes, iCloud, iMessage

2. Reset NVRAM

Shut down your Mac, then turn it on and immediately press and hold these four keys together: Option, Command, P, and R. Release the keys after about 20 seconds. This clears user settings from memory and restores certain security features that might have been altered.

3. Erase your hard drive and reinstall macOS

The best way to restore your Mac to factory settings is to erase your hard drive and reinstall macOS.