me respondo ami mismo para quien lo necesite en el futuro:
Código PHP:
<html>
<head>
<meta charset="utf-8">
<style>
.wrapper {
width: 300px;
padding: 21px;
}
</style>
</head>
<body>
<div class="wrapper">
<?php
$pm =
'<soapenv:Envelope encoding="UTF-8" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ucor="http://xxxxx.com/schemas/xxOrderRequest/">
<soapenv:Header/>
<soapenv:Body>
<identityCheck identifier="701-1813" version="2.2" worksites="?">
<customer>
<userId>xxxx</userId>
<password>xxx</password>
</customer>
</identityCheck>
</soapenv:Body>
</soapenv:Envelope>'; //aca iria en realidad el link a un xml externo (preferentemente)
$soap_do = curl_init();
curl_setopt($soap_do, CURLOPT_URL,'https://xxxxx.com/XXSoapWeb/services/ucOrders2' );
curl_setopt($soap_do, CURLOPT_CONNECTTIMEOUT, 10);
curl_setopt($soap_do, CURLOPT_TIMEOUT, 10);
curl_setopt($soap_do, CURLOPT_RETURNTRANSFER, true);
curl_setopt($soap_do, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($soap_do, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($soap_do, CURLOPT_POST, true );
curl_setopt($soap_do, CURLOPT_POSTFIELDS, $pm);
curl_setopt($soap_do, CURLOPT_HTTPHEADER, array('Content-Type: text/xml; charset=utf-8', 'Content-Length: '.strlen($pm) ));
//curl_setopt($soap_do, CURLOPT_USERPWD, $user . ":" . $password);
$result = curl_exec($soap_do);
$err = curl_error($soap_do);
//$your_xml_response = $result;
//$clean_xml = str_ireplace(['SOAP-ENV:', 'SOAP:'], '', $your_xml_response);
//$xml = simplexml_load_string($clean_xml);
echo '<pre>';print_r($result);exit;
?>
</div>
</body>
</html>
Espero que les sirva tanto como me sirvio ami cuando lo escribi xD