Today it's so easy to set up two virtual machines with your favourite OS and work through the replication chapter in the admin guide.
http://www.openldap.org/doc/admin24/replication.html
You mentioned Debian. I'd recommend not to use the Debian packages and compile OpenLDAP 2.4.36+ yourself instead.
Ciao, Michael.
Well, that does not look so easy to me (that's why I'm asking for help :) ), specially considering that I already have a working LDAP working with several hundreds users relying on them to do their work, so it's not possible to me to start from scratch, I have to use what I already have (and not break anything in the process).
For the reason above, I can't compile OpenLDAP myself (I have to use what is already there).