Add your basedn to basedn (eg: echo o=denkn,c=at > basedn). For initialization, first shutdown slapd and delete /var/lib/ldap/ (you will lost all your data!), then use ./90.root.ldif | slapadd -b cat basedn -v. Now you can start slapd again. Via ldapadd -Y external you can add any other ldif. For adding user run ./90.user.ldif.sh | ldapadd -Y external.