Use these functions to inject JavaScript and StyleSheets using Console

inject.js

var injectStyle = function(pathToStyle) {
  var head = document.getElementsByTagName("head")[0];
  var link = document.createElement("link");
  link.type = "text/css";
  link.rel = "stylesheet";
  link.href = pathToStyle;
  head.appendChild(link);
};

var injectScript = function(pathToScript) {
  var head = document.getElementsByTagName("head")[0];
  var js = document.createElement("script");
  js.type = "text/javascript";
  js.src = pathToScript;
  head.appendChild(js);
};