csrutil disable
Restart computer
In the terminal, type
sudo open /Applications/TextEdit.app /System/Library/LaunchDaemons/com.apple.ManagedClient.enroll.plist
change
<key>com.apple.ManagedClient.enroll</key>
<true/>
to
<key>com.apple.ManagedClient.enroll</key>
<false/>
So that the changes take effect
https://gist.github.com/sghiassy/a3927405cf4ffe81242f4ecb01c382ac?permalink_comment_id=4591775#gistcomment-4591775
(1) Disable SIP in 1 True Recovery
(2)
sudo rm /var/db/ConfigurationProfiles/Settings/.cloudConfigHasActivationRecord
sudo rm /var/db/ConfigurationProfiles/Settings/.cloudConfigRecordFound
sudo touch /var/db/ConfigurationProfiles/Settings/.cloudConfigProfileInstalled
sudo touch /var/db/ConfigurationProfiles/Settings/.cloudConfigRecordNotFound
(3) you're all set. enjoy this boring upgrade