<!DOCTYPE html>
<html>
<body>

<ul id="myList"><li>Coffee</li><li>Tea</li><li>Milk</li></ul>

<p>Click the button to replace the first item in the the list.</p>

<button onclick="myFunction()">Try it</button>

<p>First create a new Text node called Water.<br>Then replace the first child node of the first list item, with the newly created text node.</p>
<p><strong>Note:</strong> This example replaces only the Text node "Coffee" with a Text node "Water", not the entire LI element, which would also be an alternative when replacing nodes.</p>

<script>
function myFunction() {
    var textnode = document.createTextNode("Water");
    var item = document.getElementById("myList").childNodes[0];
    item.replaceChild(textnode, item.childNodes[0]);
}
</script>

</body>
</html>