1. Rename all part extension .kos to .rar:
-  sidel2012dec.part01.kos  to  sidel2012dec.part01.rar
-  sidel2012dec.part02.kos  to  sidel2012dec.part02.rar
-  etc..
2. Unpack
3. Burn Image ISO
4. Install
5. Use Activator to activate Windows 8
6. Enjoy