Windows install-

To run this theme in Windows, you must place the libcleanice.dll file in the
C:\Program Files\GIMP-2.0\lib\gtk-2.0\2.10.0\engines

The gtkrc file has to go here
C:\Documents and Settings\YourUserName\.gimp-2.6  folder
Sometimes it will only work in the actual program directory here
C:\Program Files\GIMP-your-version-number\etc\gtk-2.0 folder. 
(be sure and create a copy of the original gtkrc file just in case)

I have no idea where to place these files for Linux nor Mac.
I have no idea where to place these files for Windows other than XP platform.

Maybe someone can edit the file README for other platforms, and system setups.

Any questions send me a PM at www.gimpchat.com or post there and i will answer.

Enjoy the theme!

thanks,
Rod