Cutting out parts in GMAX

Does anyone know how I can cut ailerons and elevators out of a part in GMAX? I know in the tutorials you can cut certain parts and texture them for windows but I haven't seen anything that tells how to cut something out and make it a seperate part. I need to know so I can cut out geardoors and the passenger door. I've already made ailerons, rudder and elevators in FSDS, but I'm getting ready to export to GMAX for animation and final touches. Here's a pic of what I've got so far...

...any comments welcome.
Justin

...any comments welcome.
Justin