Remove Exchange 2013 CAS roles when server is already gone?

Is there a way to remove CAS roles and anything else when the server is already gone?
I have three servers EX1, EX2 and EX3.  How can I remove EX2?
Here is  what I receive with one PowerShell command.
[PS] C:\Windows\system32>Get-AutoDiscoverVirtualDirectory

Name                                    Server                                  InternalUrl
----                                    ------                                  -----------
Autodiscover (Default Web Site)         EX1
The task wasn't able to connect to IIS on the server 'EX2.example.local'. Make sure that the server exists and
can be reached from this computer: The RPC server is unavailable.
    + CategoryInfo          : ReadError: (EX2\Autodiscover (Default Web Site):ADObjectId) [Get-AutodiscoverVirtualDire
   ctory], IISNotReachableException
    + FullyQualifiedErrorId : [Server=EX1,RequestId=351ddc1e-65ff-4555-8e45-7a469fda99e1,TimeStamp=3/26/2017 5:59:41 P
   M] [FailureCategory=Cmdlet-IISNotReachableException] 30AB6771,Microsoft.Exchange.Management.SystemConfigurationTas
  ks.GetAutodiscoverVirtualDirectory
    + PSComputerName        : ex1.example.local

Autodiscover (Default Web Site)         EX3


[PS] C:\Windows\system32>