To install a theme-folder (which is just a folder containing files and some subfolders), do the following:

1. Choose Target
   [[Target options=global,single-site]]
   • If you choose to put it into global, then your root folder is
     /portals/_default/skins/
   • If you choose to put it into a single site, then your root folder is
     /portals/[your-portal-number-or-name]/skins
2. Copy your folder as a subfolder into that folder. For example, if your folder is GreatTheme you should then have a .../Skins/GreatTheme/ folder
3. Now apply it to a page or the whole site