If you want to remove a Primary Server that is designated as the MDM Server in your zone, then you must first remove the MDM role from this Primary Server.
IMPORTANT:Ensure that you do not delete all the MDM servers in your zone, as at least one MDM server is required for ZENworks to manage mobile devices. If you need to remove the last MDM server in your zone, then before removing the server ensure that you delete the Android Enterprise subscription from the zone.
To remove the role, you need to:
Click Configuration on the left hand side navigation pane in ZCC.
Click Infrastructure Management > MDM Servers.
Select one or more MDM Servers and click Remove.
NOTE:If you have removed an MDM role from a server, then you can add it back to the same server only after 30 minutes from the time the role was removed, as the cleanup action to remove the MDM role might take up to 30 minutes to complete.
Since mobile devices contact the MDM Server to which they are enrolled and if mobile devices are enrolled to a server that you have chosen to remove from the zone, then you will have to re-enroll these mobile devices to the zone using another MDM Server. Before re-enrollment, ensure that you delete the corresponding device objects in ZCC. However, if you are upgrading or replacing the MDM Server with another server, then the enrolled devices will automatically reconcile with the replaced server.