UPDATED January 14, 2017
The instructions below are for the Aerosoft Airbus A318/A319 and A320/A321.
There have been an evolution in the Aerosoft Airbus products. So far there have been three:
Airbus X. Support for this product has ended.
Airbus X Extended (Latest version is 1.16) Support for this product ended in December, 2016.
Airbus A318/A319 and A320/A321 (Latest version as of January 14, 2017 is 1.31). There is also a Bundle Package