How to remove Report Server only?
To take the Reporting Services databases out of commission on this server without disrupting the service itself, you'll need to point the service to databases elsewhere. To do this, open Reporting Services Configuration Manager on the server running the RS service, and change the "Database Name" entry in the Database menu page:



To shut down the Report Manager web portal, open up the RSReportServer.config file. This is located in the install directory (usually C:\Program Files\Microsoft SQL Server\[Instance Name]\Reporting Services\ReportServer).

Under the &lt;Service&gt; element, there will be several elements that begin with "Is". These control which services/functions are enabled. The last entry will be &lt;IsReportManagerEnabled&gt;. 



Change this value from True to False. Save the file and close. 

Some changes to RSReportServer.config require a service restart, so you may have to restart the RS service to get this change to stick. Once it does, the RS service will no longer respond to requests to the Report Manager portal but the separate web service that processes report requests will continue running.

You can read more about RSReportServer.config and switching individual services on/off here: https://msdn.microsoft.com/en-us/library/ms157273.aspx#bkmk_service