Can I install FS2002 scenery in FS2004--if yes, how?

Some scenery work and others don't. To install it you need to Unzip the folder, put it in your main scenery folder for Fs 2004,start up fs2004 go to the place where you add the scenery [archives,settings or something in that type of category] and once youv'e added it to your Fs2004 you then need to rebbot your Flight Simulator [Not the PC]. Be aware that once the scenery is installed the Afcad won't work.If you really need afcad [for Project Ai or other Ai aicraft] just go to Avsim or a similar website and download that sceneries Afcad file for fs 2004.You will need the small but handy afcad installer.

I hope this helped a bit.