George,
The 7Z file is a zip file made using 7Zip. You will need to install this program from here:
http://www.7-zip.org/ to open it.
Another compression utility that will open these files is winRAR. (I use this one)
Once you have installed either of these programs, go back to the folder you d/led the file to. Double click on the file, a new
window will open, click on the folder with left mouse button and hold, now drag the file either to your desktop or a temp folder.
Once the file is decompressed open the folder and there should be 4 folders and 3 jpg's. Klaus did not add a readme so this is
what you will need to do to install.
1st folder: FSX Addon Scenery. open this folder and there will be another folder (Codo AI Traffic 1952) add this folder to your FSX/Addon/Scenery folder.
2nd folder: FSX Sim Objekts Your AI Air Traffic. Inside this folder is the AI aircraft. If you have a dedicated AI folder you
can place them there, if not you can put them into FSX\SimObjects\Airplanes folder. (it is better to have a dedicated AI folder)
3rd folder: FSX SimObjects Boats. there are 6 folders, place these into your FSX\SimObjects\Boats folder.
The 4th folder is just screenshots, you can keep or delete up to you. (same with the 3 jpg's)
Hope this helps
Joe