You can use this to inject CSS on a page. The example shows how to use a custom badge on plug.dj

customBadge.js

// Edit the url to point to your custom badge
// Edit the data-cid to include your user ID

var css = '[data-cid^="3851534-"] .badge-box .bdg {background: url("https://ssl.benzi.io/code/qluster/images/badges/eyes.png")!important;}',
	head = document.head || document.getElementsByTagName('head')[0],
	style = document.createElement('style');

style.type = 'text/css';

if (style.styleSheet){
  style.styleSheet.cssText = css;
} else {
  style.appendChild(document.createTextNode(css));
}

head.appendChild(style);