Userscripts.org

// ==UserScript==
// @name           AMO: Better Layout
// @namespace      http://zoolcar9.lhukie.net/greasemonkey
// @include        https://addons.mozilla.org/*
// @description    Moves "Advanced Details" to top, moves "Long Description" before "More Images".
// ==/UserScript==

var addonInfo = document.getElementById("addon-info");
var addonDetail = document.getElementById("addon-advanced");

if (addonInfo && addonDetail) {
  addonInfo.parentNode.insertBefore(addonDetail, addonInfo);
  addonDetail.className = "";
  addonDetail.getElementsByTagName("a")[0].textContent = "collapse"

  var longDescTitle = addonInfo.getElementsByTagName("h4")[1];
  var longDescContent = addonInfo.getElementsByTagName("p")[0];

  if (longDescTitle && longDescContent) {
    addonInfo.insertBefore(longDescContent, addonInfo.firstChild);
    addonInfo.insertBefore(longDescTitle, addonInfo.firstChild);
  }
}