You can now drag-and-drop to customize the menu, just as you can with other browser interface elements such as the location bar or search box.
Another important interface change has been to ensure that tabs are readable.
Open Old Firefox Data folder and profile folder after that, and copy all files in it with Ctrl C button, now launch Firefox and open profile folder by visiting about:support page and close Firefox browser after that.3.
Now use Ctrl V to paste items copied earlier to Firefox default profile folder, when Windows Explorer shows “confirm folder replace” dialog, at the bottom of it select “Do this for all Current items” (check the screenshot below) and click “Yes” button. Next ‘Copy File’ dialog appears on screen with message “there is already a file with the same name in this location, select ‘Do this for next (number shown) conflicts’ at the bottom, and click on ‘copy and replace’. Your old Firefox profile data has been restored, open Firefox and check to confirm that.
Scroll down to step 1 to easily update your Firefox plugins.