In this article I will explain you how to remove css class using jquery. If you want to remove css class by the removeClass attribute. Here I am already applied test1 class to the div element. Click event I am removing the test1 class and applied test2 class.
<!DOCTYPE html><html><head><title>apply css styleusing Jquery </title><script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.5.1/jquery.min.js"></script><style type="text/css">.test1 {background-color: yellow;color: Red;}.test2 {background-color: gray;color: White;}</style></head><body><input type="button" id="button3" value="click me" /><div id="divTest2" class="test1">hello and welcome</div><script type="text/javascript">$("#button1").click(function () {$("#divTest2").removeClass('test1').addClass('test2');});</script></body></html>