The users will have to install the theme the old fashioned way
The second version of the Windows 8 modern UI theme has been released for the Linux platform and comes with a few fixes.The Windows 8 modern UI (metro) theme for GTK and metacity does exactly what the name implies, it makes your operating system look like Windows 8.
“Why?” is usually the question on everyone's mind. Microsoft was the first company to introduce the flat and minimalistic themes and there are a number of Linux users who enjoy the way Windows looks. This new version features a reworked GTK3 version and a theme.index file.
The installation of the two themes works just like any other. You will have to place the files in /usr/share/theme. You can then use something like GNOME Tweak Tool in order to activate them.
Download Windows 8 modern UI (metro) theme for GTK
Download Windows 8 modern UI (metro) theme for metacity