Putting Map files in Blitzkrieg 2\EXE\Data will not change game, don't copy any MOD files in that folder please as that will corrupt game!!!
There is an extra mod folder: Blitzkrieg 2\EXE\mods
After you click download link you will come to Box.net
(feel safe as the pak file is not executable and has no virus in it)
click on download butten and
you will be ask where to save file, or file is automaticly saved in „download folder“
To play map you need to copy the mapfile, in this case „Ardenne_01_SP.pak“, into the
Blitzkrieg 2\EXE\Data folder
paste into Blitzkrieg 2\EXE\Data folder
Now start BK2 and new map is availible in custom missions or in multiplayer,
depending what map it is!