Eg : You want to install topicons, from extensions.gnome.org/extension/495/topicons/. From the extension homepage, you can find the latest version source (as of may 2015) :
% cd ~/.local/share/gnome-shell/extensions % wget http://184.108.40.206/repo/topicons/snapshot/topicons-26.zip % unzip topicons-26.zip # you can edit and check the extension % grep uuid topicons-26//metadata.json "uuid": "topIcons@email@example.com", % mv topicons-26 topIcons@firstname.lastname@example.org
You should now be able to enable the extension from gnome-shell-extension-prefs.
If the extension does not show up as it happened with me, you should try to reload gnome-shell (alt+F2, r, then enter).