Read Soap services in .net

I have to read data published on soap-services.

I have the WSDL of the soap service.

In order to request the data or to connect to that soap-service, first of all, I have to connect using userid/password.

Then I have to pass a request whose xml looks like this -

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:cm="http://oracle.com/mysoapservices.xsd">
   <soapenv:Header/>
   <soapenv:Body>
      <mysoapservices>
    <request>
        <assignmentId></assignmentId>
        <needCompletionDetails>Y</needCompletionDetails>  
        <hostSystem>myhostsystem</hostSystem>
    </request>  
      </mysoapservices>
   </soapenv:Body>
</soapenv:Envelope>

That request will send a response, which will also be xml-format...
I have to write that data to a database . I can do like whats mentioned in  https://msdn.microsoft.com/en-us/library/bb628652.aspx but I have to  access the data  by passing that xml-request object and getting xml-response object...

How should i do it.  I want to do it in .net

Thanks so much...