The file in this archive, CSArena4.exe, is a self-extracting archive compressed with the 7Zip file compression utility. 7Zip is similar to ZIP and RAR, but produces smaller files. 

Run the self-extracting archive and unpack the CSArena4" folder inside to some location on your harddrive (NOT the game's override folder). Then run the "Install Arena.exe" installer (found inside that folder) to install the Combat Simulation Arena mod.

Plase see the ReadMe file inside the unpacked CSArena4 folder for more information about this mod.

