lorem-bacon-jquery.js

function injectJquery(callback) {
  if (window.jQuery) {
    return callback(window.jQuery);
  }
  let script = document.createElement('script');
  script.setAttribute(
    'src',
    '//ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js'
  );
  script.onload = () => callback(window.jQuery);
  script.onerror = e => alert('The script failed to load: ' + e);
  document.head.appendChild(script);
}

injectJquery(function($) {
  let html = $('body').html();
  html = html.replace(/Lorem/g, 'Bacon');
  $('body').html(html);
});