Read the instructions. The site has them just to be read, you know.

Simply you download the installer, which is the program that installs the packages inside your FS9, and extract it in a folder of your choice, then download the various packages with the AI. Then you (for simplicity's sake) unzip the .PAI files inside the same folder where you extracted the installer and start the installer itself following the instructions on screen.

It's simple enough.

PS
If you have installed a Soundblaster audio card the installer will not start unless you first terminate the CTHELPER.EXE process from the active processes. Simply right-clicking on the bar and choosing "task manager", select the CTHELPER.EXE process with a right click and choose "terminate".
If you don't have a Soundblaster card, then simply disregard these last words.

There's but one real cure for human stupidity. It's called DEATH.
At the moment mourning the assassination of sarcasm and irony for the good of the "higher".
Proud FSIX user. Active user of FS98, X-plane and novic