Download the library with bower, npm, git or als a zip file here:
Bower: bower install supersloth.js
NPM: npm install supersloth.js
Git: git clone https://github.com/kriskbx/supersloth.js.git
Copy and paste this code right before the body tag of your website, make sure to replace the url:
<script type="text/javascript" src="supersloth.js"></script>
Run this to get the slothy awesomeness: superslothjs.start();
Aaaaand, that's it.