First of all if you don't already have it you need a programme called Winzip, you can get it free at
http://www.winzip.com This programme allows you to 'unzip' your files into (for example) a new folder on your desktop.
Now through windows explorer open
program files/microsoft games/fs2000/aircraft
And you'll see a folder for each of the aircraft that came with the programme, if you look in each folder you'll see it consists of four other folders marked model, panel, sound and texture.
Create a new folder here with the name of your new aircraft and place in it the four folders you've just unzipped, I use cut and paste between two explorer windows.
Sorry if I've made it seem over complicated and there may be an easier way, but this way works for me.
Let me know how you get on.
[ 22 July 2001: Message edited by: Pengineer ]