Which four actions should you perform?

Explanation/Reference:
Explanation:
On Server1, move the conference directories.
On Server1, deactivate all of the Office Communications Server 2007 R2 components.
On Server1, uninstall the Office Communications Server 2007 R2 components.
On Server2, remove the BackCompatSite.
Note:
* Decommission Legacy Site, main steps:
Move Conference Directories
Update DNS SRV Records
Decommissioning Servers and Pools
Remove BackCompatSite
* Move Conference Directories
Before decommissioning a pool, you need to perform the following procedure for each conference directory in your Office Communications Server 2007 R2 pool.
Move a conference directory to Lync Server 2013
* After all pools are deactivated and all Edge Servers have been uninstalled, run the Topology
Builder Merge wizard to remove the BackCompatSite.
* Before decommissioning a Standard Edition server or a server in an Enterprise pool, do the following:
Provide users with sufficient notice to ensure that they can plan for the down time.
Deactivate the server roles on the weekend or holiday, or during other off-peak hours.
Reference: Decommission Legacy Site