ok, im about to start pulling my hair out, lol i cannot get these posky 737's to read into FSX let alone get the VC in.
You need a good basic knowledge of FS aircraft structure before attempting this. I suggest you concentrate on one version of the latest Posky 737 before going any further. Once you have that working in FSX you can try adding the VC.
First you need to download & install one of the Base Packages for your chosen 737.
http://www.projectopensky.com/downloads-index.phpInstallation should be straightforward enough & no different from any other 3rd party aircraft in FSX.
All you really need is the AIR file & Aircraft.cfg as everything else will be replaced. The easiest way to convert this for FSX is to paste copies of the Panel & Sound folders from the FSX default B737_800 into the main folder of your new 737, overwriting files/folders when prompted. The new aircraft should now be listed on the FSX aircraft selection menu but without a thumbnail image. You can fix this later when you add the VC. The important thing is to get it working in FSX.