You can do this in 2 ways.
You can disable the plugin css by setting Use plugin css file to No. Then copy this plugin’s css code and put inside theme’s css file. Now modify this css code to load images from your site. This approach allows you to achieve the result without touching the plugin files.
You can also achieve the same thing by modifying the plugin css file wti_like_post.css present inside css folder. You can put your images inside the images folder and reference them from the css file.
In either case, you can refer the coding available for the Style1 so that it will be easier for you to code.
Thanks
