We use
replaceChild() to replace elements
<div id="div1">
<p id="p1">TechFunda.</p>
<p id="p2">DotNetFunda</p>
</div>
<script>
var a = document.createElement("p");
var b = document.createTextNode("ITFunda");
a.appendChild(b);
var c = document.getElementById("div1");
var d = document.getElementById("p1");
c.replaceChild(a, d);
</script>
We created element p with text as ITFunda by using replaceChild(a,d); it replaces the value TechFunda with ITFunda