I have had a customer needing to revert back from a Cisco Communication Manager synced with Microsoft Active Directory to a stand alone Cisco Communication Manager.
This turned out to be relatively simple to resolve.
You need to first remove all the LDAP configuration from the Cisco Communication Manager
Delete the LDAP Configuration –> Disable the Integration –> Deactivate the DirSync Service from servicability.
All the users at this point will be converted to normal standard cucm users.
Once this has been completed the open up a console connection to the cucm and run this command.
run sql update enduser set status=1
this will then make all the users active again on the system.
You may find that you get a memory allocation error using the sql update command if you have a few users configured. in my case there where 4000+ users so i had to use a slightly altered command
run sql update enduser set status=1 where telephonenumber like ‘2%’
we then just changed the number in the telephone number from 0 to 9 which did all users in batches.
to make sure you got all the users you can use the command
run sql select * from enduser where status=0
if you got them all then this should return no enteries