<title>jQuery removeClass()</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
.highlight{font-size:18px;color:#11a286}
$(document).ready(function() {
$("#button").click(function() {
$("p").removeClass('highlight');
<p class="highlight">This is a paragraph.</p>
<button style="margin:0 0 10px 0;background:#e8e8e8;" class="btn" id="button">Click here to remove class from p element</button><br />