I have just downloaded an AFCAD file for my local airfield. There are buildings in the way of the parking stands. How do I remove the buildings from FS or the AFCAD file so I can park on the stands.

Is the AFCAD for default scenery or for another 3rd party scenery? If you're using default scenery and the AFCAD is for 3rd party or vice versa that might be the problem. If the AFCAD is for the default scenery and you are using default scenery, then it is most likely a mistake by the AFCAD creator.

It would help if you told us what airport you were talking about and which AFCAD you had installed. Was it really an AFCAD, or did you install files replacing the whole airport.To answer you direct question, I would use a combination of Worldwind to get a picture of the airport, and then use the picture of the airport as a background map in SceneGenX to create appropriate exclude areas. You may also want to use AFCAD2 to modify the existing AFCAD as well if you see other errors. I also run FS at the same time and use the airplane to locate where I need to put things in both SceneGenX and AFCAD2.Thomas