As this aircraft is already in game, you will only need to install a "new" cockpit.
The improved version of the cockpit is here.
If you have not modified your game yet, and do not want a monster download I would recommend this as a choice.
Getting the mod for the FW.200C-3/ U-4 into the game: you may find this helpful...
...which also has helpful links for putting planes in the air via the SAS method, and faultfinding if it doesn't work.