replace
by dshilkret
HTML
<div class="right-div" width="50%" height="512" >
<a href="https://sdev2.sharepoint.com/:x:/r/_layouts/15/WopiFrame.aspx?sourcedoc=%7BF5CBC55F-C6F0-4751-98AB-31F9162F29CD%7D&file=clauses.xlsx&action=embedview" target="docFrame">Test Clauses</a>
<p id="demo">https://sdev2.sharepoint.com/_layouts/15/WopiFrame.aspx?sourcedoc=%7BF5CBC55F-C6F0-4751-98AB-31F9162F29CD%7D&file=clauses.xlsx&action=default</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
var str = document.getElementById("demo").innerHTML;
var res = str.replace("https://sdev2.sharepoint.com/", "https://sdev2.sharepoint.com/:x:/r/");
document.getElementById("demo").innerHTML = res;
}
</script>
<iframe name="docFrame" frameborder="0" scrolling="no" src=""></iframe>
</div>