Yes, its possible to change the image. Please put your images inside the plugin image folder. You may have to change the plugin css file accordingly. Please see the different image (up arrow) implementation here http://www.denimarchive.com/
Hello, thank you for the quick response. I added my custom image to the plugin image folder. However, when i try to edit the CSS to change the name of the image, it does not update the image on my site. Also, when I edit the CSS for the plugin, it states that the CSS file is inactive. However, the plugin is active. This is the message:
Editing wti-like-post/css/wti_like_post.css (inactive)
Am I editing the wrong CSS file?
Probably the best way will be using an image of same height and width with the same name which is there on the system. this way you will have to do minimum modifications of the css file.
Please refer to http://wordpress.org/support/topic/plugin-activated-related-css-files-inactive?replies=3 for the plugin inactive issue. I have never faced such type of problems ever.