How to restore your Mac from the macOS Monterey beta to Big Sur
The Verge
JULY 1, 2021
The path to restoring is easiest if you made a Time Machine backup before updating the operating system, or if you installed the beta on a separate partition via Disk Utility. If you installed the beta on your main partition without a backup, you can still restore your system to the older OS, but you’ll need to start fresh.
Let's personalize your content