[CentOS] move LDAP service to new server

On my old Centos 7 server I had set up a LDAP database for user authentication 
by other services (the server locally uses normal PAM authenticatin).

I set it up originally from a web page describing how to set up an LDAP server 
for use with MS Outlook clients (which never worked)

Is there any (easy to follow) instructions anywhere to tell me how to back up 
this service and restore it onto a new one?