You can install the Classic Theme Restorer extension to restore some functionality that was lost with the arrival of the Australis code in Firefox 29.

• https://addons.mozilla.org/firefox/addon/classicthemerestorer/

• https://support.mozilla.org/kb/how-to-make-new-firefox-look-like-old-firefox

• https://support.mozilla.org/kb/common-questions-after-updating-to-new-firefox
• https://support.mozilla.org/kb/learn-more-about-the-design-of-new-firefox

Install Stylish Add-on for Firefox https://addons.mozilla.org/de/firefox/addon/stylish/ .

Create a new style under Add-ons -> User Styles and copy the following text into the biggest of the three boxes:

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");

@-moz-document url("chrome://browser/content/browser.xul") {

 #PanelUI-button, #customization-panel-container,

 #customization-panelWrapper .panel-arrow,

 #ctr_panelui-button,

 #wrapper-ctr_panelui-button {

   -moz-box-ordinal-group: 0

 }

 #PanelUI-button {

   background-position: 100% 0, calc(100% - 1px) 0, calc(100% - 2px) 0;

 }

}

End of Text (Don't copy this line.)############

Save and restart. The Button should be on the left now.

See also:

• https://userstyles.org/styles/94907/australis-menu-button-on-the-left.css