Download the amazing campaign user manual here, and although could seems obvious, read it carefully to fully comprehend this campaign system.
Download the Newtonsoft libraries the system needs to work with here. Those libraries must be unzipped in the Steam game directory.
[unidad]:\[steam installation path]\Steam\SteamApps\common\il-2 sturmovik cliffs of dover
Download the campaign of here and unzipped it in the "missions" directory of the game located in "my documents".
[unidad]:\Users\[your windows user]\Documents\1C SoftClub\il-2 sturmovik cliffs of dover - MOD\missions
Edit the conf.ini (If you aren´t going to use a dedicated server) or the confs.ini (If you are using a dedicated server) and add the following line.
scriptAppDomain = 0
Important! If you do not add this line the system will not be able to read the commands from the chat.
Regarding using a dedicated server (highly recommended) there is enough information about it in the 1C official forum here.
Ve al directorio de la campaña en:
[unidad]:\Users\[tu usuario de windows]\Documents\1C SoftClub\il-2 sturmovik cliffs of dover - MOD\missions\hrcodwar
Edit the conf.ini and in allied_squadrons or axis_squadrons add the squadron nick. Then, in the commanders list allied_commanders or axis_commanders add your complete nick.
Be aware that if the system does´t detect your squadron nick will not let you flying and if, in the commanders list, doesn´t detect your nick will not let you run any management commands.
Finally, in the same directory you will see a subdirectory called /templates , rename anyone of those with your squadron nick.
Can you see now how neccesary was step 1?, All those steps are quite non specfic and can´t be used in a "real campaign" but will allow you to make sure everything is working as it should.