How Consume WebService (SOAP) on Android App

Hi, I'm using Xamarin.Forms targeting Android, I want to consume web services (SOAP). I have built in VS 2012 + plugin Xamarin. I need a tutorial guide or personal help for this.
The SOAP WebService is:

SOAP 1.1

The following is a sample SOAP 1.1 request and response. The placeholders shown need to be replaced with actual values.

POST /api/UsuarioWS.asmx HTTP/1.1
Host: puenteseducativos.intercapit.com
Content-Type: text/xml; charset=utf-8
Content-Length: length
SOAPAction: "http://microsoft.com/webservices/Login"

<?xml version="1.0" encoding="utf-8"?>



string
string



HTTP/1.1 200 OK
Content-Type: text/xml; charset=utf-8
Content-Length: length

<?xml version="1.0" encoding="utf-8"?>



string

Thanks you.