You need a SOAP capable client for this.
After you defined your web service in SE80 you need to configure it in transaction SOAMANAGER. You can refer to the below link:
http://wiki.scn.sap.com/wiki/x/6owxDQ
Once you have a working endpoint, a so-called binding, you need to send a valid SOAP request over HTTP POST to this endpoint, the binding or service URL. You can find this service URL at the bottom of the WSDL file in the tag <soap address..>
The WSDL file is an XML schema that describes the web service. The below link shows how to locate the WSDL in SOAMANAGER:
http://wiki.scn.sap.com/wiki/x/eInuDg
Note the difference between the WSDL URL and the service URL
WSDL URL - the location of the WSDL file that describes the service
service URL - the endpoint of the actual service
