You got to overwrite the old files.
Open up the game folder where game.exe is.
Open the archive in winrar since you got that. Go down one folder until you see "game"
There is a "game" folder in the game directory, there is a "game" folder in the archive, drag the "game" folder from the archive into the game directory, windows should complain about overwriting files which is a sign you did it correctly, overwrite those files, and enjoy.