<?php
$xml = new DOMDocument;
$xml->load('inimesed.xml');

$xsl = new DOMDocument;
$xsl->load('inimesed4a.xsl');

$proc = new XSLTProcessor;
$proc->importStyleSheet($xsl);
$proc->setParameter('', 'pikkus', '3');

echo $proc->transformToXML($xml);
?>