I think you can delete it from Windows Services.
You can use below steps to delete this service.
Open Central Configuration manager (CCM) and stop the Server Intelligence Agent (SIA) to be deleted.
Next is to go to Windows Start > Run and type in "services. MSc" without the quotes and press Enter key. In the Services applet, find the SIA service to be deleted say Server Intelligent Agent (BI40) as shown in first snapshot.
Go to Properties of Server Intelligent Agent (BI40) and navigate to “General” tab -> Copy the Service name BOEXI40XXXXX to the clipboard.
Next is to open command prompt and run following command: sc delete BOEXI40SIABI40.
Navigate to "Install Directory\Program Files (x86)\SAP Business Objects\SAP Business Objects Enterprise XI 4.0\win64_x64" directory and delete the following files for Server Intelligent Agent (BI40).
Also note that if you delete all SIA it will shut down your server. You have to ensure that you have multiple SIA’s and you are deleting the right one.