Tried again and all I get is Instructions.
What else you were expected to find ? If you read the instructions, it would be clear what's being installed ( Some example Simobjects ) and how to use it.
You were expecting some kind of software ? There's no need to install or use any software to use the PaintKit, just create a texture with your airline logo, and edit the USER Simobjects according to the instructions to assign to airports.