edit xml with php?

Hi! I am trying to edit this xml-file: I want to change one of the li-nodes. <?xml version="1.0"?> <kund> <li> <na>per</na> <en>Bylund</en> <ga>Semin</ga> </li> <li> <na>Axel</na> <en>Timan</en> <ga>Semina</ga> </li> <li> <na>Lars</na> <en>Berg</en> <ga>Seminar</ga> </li> </kund> ------------- I have tryed to read and explode on "</li>" $fd = fopen($filename, "r"); $string = fread($fd, filesize($filename)); $fru = explode ("</li>", $string); for ($i=0;$fru[$i];++$i) { $newfru = ("$fru[$i]"."</li>"); $newfru = str_replace("</kund>"."\r\n"."</li>","</kund>",$newfru); print $newfru; } How to replace one of the $fru[i], I have tryed inside the forloop but than it replaces all. Thanks in advance for any help. Regards Jan