You can use PHP's built in SOAP library to create a SOAP client and call a method from the WSDL, try something like this:
$client = new SoapClient($wsdl, array( 'soap_version' => SOAP_1_1,
'trace' => true,
));
try {
$params = array(
//Your parameters here
);
$res = $client->__soapCall( 'SoapMethod', $params );
return $res;
} catch (SoapFault $e) {
echo "Error: {$e}";
}
//for debugging what the outgoing xml looks like
$client->__getLastRequest();
The WSDL should help structure the xml for your params. If you cannot get that to work the way you want you could try passing the xml yourself using SoapVar() and setting the encode to XSD_ANYXML.
If you also need to add additional header information take a look at this example from the PHP docs.