1. Rename "part.kos" to "part.rar":
-  bboxfar3cry.part01.kos to bboxfar3cry.part01.rar
-  bboxfar3cry.part02.kos to bboxfar3cry.part02.rar
-  etc..
2. Unrar
3. Mount or burn it
4. Run setup.exe
5. Start the game from desktop
6. Support game developers like we do