Regarding the Navigraph AIRAC update for EFB:
The main website from Navigraph at http://www.navigraph.com (home page), by the "Navigraph FMS Data" label, click at the "Download Now button. This is where one gets the AIRAC updates for other add-ons (PMDG, FS Comander, etc). here you need to look down for Aivlasoft EFB. Click there and download the zip file with the update.
Then proceed to execute the update, which works just like updating PMDG, FS Commander and the others.
You must know the path to the folder where EFB expects that nav data, which is in the same PC where you run the data provider (The FSX machine).
I think you need to have EFB off to do the update, and then restart the EFB data provider for the update to become active.
Alvaro Escorcia