That is not the way to access a SOAP Web service. That functionality is only available as a "crude HTTP GET access mechanism" (Test a SOAP Endpoint) for a quick test - which explains why there is so little information about it.
You may want to re-consider your choice of using JWS files:
Important: JWS web services are intended for simple web services. You cannot use packages in the pages, and as the code is compiled at run time you can not find out about errors until after deployment. Production quality web services should use Java classes with custom deployment.