Download the zip file and extract it. run the setup and install the mod into your original commandos 2 men of courage directory. start the game and enjoy!
It does not matter if you are using the CD version or steam version of the game it works on both legacy and steam edition.
If you can not input the correct path to the installtion, simply run the setup and install the files somewhere else and open the "DATA" file which you have acquired after installtion then copy and paste the belongings to your original "DATA" folder in your original commandos 2 folder.