If you run the command:
sc queryex <service name>
where is the the name of the service, not the display name (spooler, not Print Spooler), at the cmd prompt it will return the PID of the process the service is running as. Take that PID and run
taskkill /F /PID <Service PID>
to force the PID to stop. Sometimes if the process hangs while stopping the GUI won’t let you do anything with the service.