The final step is to delete the BackCompatSite in the Lync Topology Builder and decommission the OCS 2007 R2 Servers. Follow the steps that follow to perform the decommission process:
1. Open the Topology Builder tool on the Lync Front End Server.
2. Select the BackCompatSite.
3. Click Delete in the right Action pane.
4. A warning pops up saying the site is not empty. Click OK to delete it anyway.
5. Republish the topology by clicking the Lync Server 2010 item in the left pane. Then click Publish Topology in the right Action pane.
6. Click Next to begin the process.
7. Ensure that it finishes successfully and the BackCompatSite object is deleted from the topology.
8. Log in to the OCS 2007 R2 Server.
9. Open the OCS 2007 ...