Copy this files into your EF2 folder:

Brown3d.bmp
Brown4d.bmp
Brown5d.bmp
Green3d.bmp
Green4d.bmp
Green5d.bmp
icons3d.bmp
icons4d.bmp
icons5d.bmp
Mud3d.bmp
Mud4d.bmp
Mud5d.bmp
Snow3d.bmp
Snow4d.bmp
Snow5d.bmp
Terrain1d.bmp
Terrain2d.bmp
starshell.bmp
starshell.exe

and the icon2d.bmp from you dowloaded

to alter an EF2 scenario to a night scenario, open the .scn file with a text editor, search a line that looks this:
0 0 0
alter the first number to 1, that makes the scenario to a night scenario.
the second number specifies the startshell for axis the third for the allies (or vice versa)

save the file.
enjoy.