help is in instructions in post one and in cityXplorerEU thread :
How to unlock a CX map ? (37xx series excluded)
You must create the .unl file with PID 2 and the FID of the related City Navigator-
Enable additional fields in Jetmouse keygen and insert PID 2 and the right FID-
Copy the anyname.img (eg. Paris.img) and anyname.unl (eg. Paris.unl) in "Map" folder in your sd-
If it's the small cityXplorerEU.img (the one with just MMR files )you must have the related CNE in your nuvi.