How to disable MDM/DEP notifications from macOS Big Sur to Sonoma

This post will allow you to disable/prevent MDM/DEP Notifications and macOS POPUPS forcing you to join an organization's MDM.  This would be handy if a computer was purchased and not removed from Apple's MDM.

Restart the mac in Recovery Mode Restart your Mac then hold down the Command + R keys together until you're in the Recovery Mode

From the menu bar Click on Utilities then select: Startup Security Utility

A popup appears with 3 choices; select (No security) and restart
NOTE:  There is no confirmation notification or button to press

When the system reboots hold down Command + R to get back into Recovery Mode.

Click on Utilities from the top menu bar then select Terminal

In terminal type: mount then press enter/return

A list of devices will show up in a list.  You will want to use the volume that specifically says "/Volumes/Macintosh HD"

In my case it is /Volumes/Macintosh HD (/dev/disk3s4) 

NOTE: it's not "/" (root), and it's NOT /Volumes/Macintosh HD - Data

In Terminal Write:

1. umount /Volumes/Macintosh\ HD
2. mkdir /Volumes/Macintosh\ HD
3. mount -t apfs -rw /dev/disk3s4 /Volumes/Macintosh\ HD
4. cd /Volumes/Macintosh\ HD/System/Library/LaunchAgents
5. mkdir xtemp
6. mv com.apple.ManagedClientAgent.* xtemp/
7. mv com.apple.mdmclient.* xtemp/
8. cd ../LaunchDaemons
9. mkdir xtemp
10. mv com.apple.ManagedClient.* xtemp/
11. mv com.apple.mdmclient.* xtemp/
12. csrutil authenticated-root disable (this will Turn off Signed System Volume SSV)
13. bless --folder /Volumes/Macintosh\ HD/System/Library/CoreServices --bootefi --create-snapshot
 (this will Save the current disk status in the boot snapshot)

Now you can restart your Mac, and DEP notifications are disabled.