Back up any important files
Sign out of iCloud
Sign out of iMessage
Sign out of FaceTime
Unpair Bluetooth devices if needed
Restart the MacBook Air
On Apple silicon MacBook Air, shut down the Mac
Press and hold the power button until startup options appear
Click Options
Click Continue
On Intel MacBook Air, restart and immediately hold Command + R
Open Disk Utility
Select Macintosh HD
Click Erase
Erase the startup disk
Quit Disk Utility
Select Reinstall macOS
Follow the on-screen instructions
If using macOS Ventura or later, open System Settings
Go to General
Click Transfer or Reset
Click Erase All Content and Settings
Follow the prompts
Wait for the reset to complete
Set up the MacBook Air again or shut it down for the next user