Uninstall Exchange Server 2007 from Passive node

• Login to passive node and check whether Exchange CMS is located on active node with Get-ClusteredMailboxServerStatus cmdlet from EMS
• Run:

  C:\Program Files\Microsoft\Exchange Server\bin\Setup.com /mode:uninstall

Evict pasive node from Windows Cluster

• Stop the Cluster service by running:

  net stop clussvc

• After the Cluster service has been stopped, evict the node by running:

  Cluster <ClusterName> node <NodeName> /evict

Remove CMS from Active Node, uninstall Mailbox role & destroy Cluster

• Login to active node and run:

  C:\Program Files\Microsoft\Exchange Server\Bin\Setup.com /mode:uninstall /removeCMS /CMSName:<CMSName>

• Destroy Windows Cluster (Right click on the cluster name then choose More Actions > Destroy Cluster in Failover Cluster Management)