Steps to change logo image in joomla for JA Purity Template:

1.Create your own logo file in .png and .gif format e.g mylogo.png & mylogo.gif

2.Open the image in Paint and Get its accurate size .

3.Login in Joomla as administrator

4.Go to Extension Tab.Select Template manager.

5.Select JA PURITY and click on Edit button on top right corner.

6.Click Edit CSS Button.Select template.css and click Edit.

7.Search for logo.png and replace it with new image name.

8.Change the values of width and height by the values which you got from paint editor.

h1.logo a {
 width: 968px;
 display: block;
 background: url(../images/mylogo.png) no-repeat;
 height: 140px;
 position: relative;
 z-index: 100;
9.Save the CSS

10.Rename or delete logo.png and logo.gif from original localtion.In this case location is