Back up any files you want to keep
Sign out of iCloud
Sign out of Messages
Sign out of Music, TV, and App Store accounts
Turn off Find My Mac
Unpair Bluetooth devices if needed
Restart the MacBook
On Apple silicon Mac or Intel Mac with T2 chip, hold the power button to enter startup options
Select Options, then click Continue
Enter an administrator password if prompted
Open Disk Utility
Select the internal drive
Click Erase
Choose APFS if prompted
Confirm the erase
Quit Disk Utility
Select Reinstall macOS
Follow the on-screen instructions
Let the installation complete
Shut down the MacBook if you are selling or giving it away
If using macOS Monterey or later, use Erase All Content and Settings from System Settings if available