The Front End Server migration is a bit more involved and requires more steps to complete successfully. The first step is to prepare Active Directory for Lync Server 2010.
After the Central Management Store is created and populated with a base topology, the administrator must import the legacy OCS 2007 R2 topology and configuration.
Before proceeding, ensure the OCS WMI Backward Compatability pack is installed. It is located on the Lync Server installation media at Setup\amd64\Setup\OCSWMIBC.msi.
On the Front End Server, open the Lync Management Shell and enter ...