Inténtalo tú mismo - XML dom

<!DOCTYPE html>
<html>
<body>

<p id="demo"></p>

<script>
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
   if (xhttp.readyState == 4 && xhttp.status == 200) {
   myFunction(xhttp);
   }
};
xhttp.open("GET", "books.xml", true);
xhttp.send();

function myFunction(xml) {
   var x, i, xmlDoc, txt;
   xmlDoc = xml.responseXML;
   x = xmlDoc.getElementsByTagName("title");
   // Add a new attribute to each title element
   for(i = 0; i < x.length; i++) {
   x[i].setAttribute("edition", "first");
   }
   // Output title and edition value
   txt = "";
   for (i = 0; i <x.length; i++) {
   txt += x[i].childNodes[0].nodeValue +
   " - Edition: " +
   x[i].getAttribute("edition") + "<br>";
   }
   document.getElementById("demo").innerHTML = txt;
}
</script>
</body>
</html>