Restart the simulator, and the airport will be upgraded automatically.
Extract the folder named lfsj-rivierascene (or similar) from the zip. Drag and drop that folder into your MSFS folder. lfsj_rivierascene.zip
The file refers to a custom scenery package for Microsoft Flight Simulator (MSFS) featuring the Chambéry - Challes-les-Eaux Airport (LFSJ) in France. Restart the simulator, and the airport will be