on the image of removed files the gmapprom.img is your main map file, the one in the expanded map folder called city navigator ntu 2017.img is also a map image but looking at the size of it compared to the deleted one i would say it is not a complete europe map 4gb vs 2.2gb. i dont see a gmap3d.img anywhere and you say the JCV folder is empty, that seems odd but it would not stop the unit from working or downloading, in fact it would give you more space as they are largish files. when you have your new card remove the small one and replace with the new one formated correctly connect it to your mac and run express it should show available update or reinstal update, not sure on a mac but there should be an advanced setting to save to pc and device make sure you choose that, sit back and let it run,some people have said they have had an issue with express and their macs giving errors and not installing the maps, i can not comment on this as i dont have a mac, but unless it flags up an error let it run till it is finished, and i would advise against doing the update over a wireless connection, plug into the router or network via a cable.
