Q: How to restore the original icons for Mozilla Firefox?

1. Read General Notes

2. wget -c https://frankandjacq.com/ubuntuguide/mozilla-firefox.png
   wget -c https://frankandjacq.com/ubuntuguide/document.png
   chmod 644 mozilla-firefox.png
   chmod 644 document.png
   sudo dpkg-divert --rename /usr/share/pixmaps/mozilla-firefox.png
   sudo dpkg-divert --rename /usr/share/pixmaps/mozilla-firefox.xpm
   sudo dpkg-divert --rename /usr/lib/mozilla-firefox/icons/default.xpm
   sudo dpkg-divert --rename /usr/lib/mozilla-firefox/icons/document.png
   sudo dpkg-divert --rename /usr/lib/mozilla-firefox/chrome/icons/default/default.xpm
   sudo cp mozilla-firefox.png /usr/share/pixmaps/mozilla-firefox.png
   sudo cp mozilla-firefox.png /usr/share/pixmaps/mozilla-firefox.xpm
   sudo cp mozilla-firefox.png /usr/lib/mozilla-firefox/icons/default.xpm
   sudo cp document.png /usr/lib/mozilla-firefox/icons/document.png
   sudo cp mozilla-firefox.png /usr/lib/mozilla-firefox/chrome/icons/default/default.xpm

3. Read How to restart GNOME without rebooting computer?