Restore Shipping Software
To use a previously-released OS version, you can erase your device, then restore from the backup that you created before you installed the beta.
Intel-based Mac:
Turn off Find My Mac and sign out of your Apple ID
To turn off Find My Mac, go to System Settings > Apple ID > iCloud > Find My Mac, and toggle Find My to OFF.
Then click the back button to return to System Settings > Apple ID, and click “Sign Out…” to sign out of your account.
Back up your Mac
Back up your Mac using Time Machine.
Start Internet Recovery
Boot to Internet Recovery (Option-Command-R or Option-Shift-Command-R) to prepare to downgrade to the version of macOS that came with your Mac or the closest version that’s still available.
Erase volume group
Open Disk Utility and select “Macintosh HD”. Select the “Erase Volume Group” (not just the volume “Macintosh HD”). You may have unexpected results if you do not select ”Erase Volume Group”. When complete, quit Disk Utility.
Reinstall macOS in Internet Recovery
Click on Reinstall macOS and follow the onscreen instructions. If Find My was enabled on the Mac, you will need to activate the Mac when the reinstall process completes. At the end of the activation process, you will be prompted to restart the Mac. More details about reinstalling macOS are available here.
Follow the macOS Setup Assistant
At the appropriate time, select the option to restore data from a Time Machine backup. Select the backup that was completed at the start of this process to restore the Mac’s data.
Mac with Apple silicon:
Turn off Find My Mac and sign out of your Apple ID
To turn off Find My Mac, go to System Settings > Apple ID > iCloud > Find My Mac, and toggle Find My to OFF.
Then click the back button to return to System Settings > Apple ID, and click “Sign Out…” to sign out of your account.
Back up your Mac
Back up your Mac using Time Machine.
Restore with Apple Configurator 2
Use the following procedure to restore a Mac with Apple silicon with Apple Configurator 2.
Follow the macOS Setup Assistant
At the appropriate time, select the option to restore data from a Time Machine backup. Select the backup that was completed at the start of this process to restore the Mac’s data.