You need to download the service manual, and follow the instructions there when it comes to removing the aluminium plate around the platter. Careful when removing it to avoid scratching anything. You shouldn't need to remove the plate above the indicator bar. Just leave that in place during transport, but make certain that it can't get free and begin clattering about inside the turntable. Don't use tape to fasten anything made of aluminium.
There are transport screws underneath the turntable, which you fasten once you've removed the platter.
Make certain that you don't lose the drive belt - you'll figure out how that comes off easily.
Remove the cartridge from the arm - pulling it straight out while holding on the the arm with the other hand. Store the cartridge safely, and where the stylus is protected.
Put the platter inside something where it is well protected from scratches, and where it can't bump against the deck. Try to avoid having to take the lid off, but make certain it doesn't clatter up and down. I'd probably go with a satchel bag for the platter and a separate bag for the deck. I wouldn't want to fly with it as checked baggage and would do what it takes to get it into the cabin with me.
There's a trick to removing the plate above the position indicator bar. A lot of people don't know it, and therefore end up denting the top right corner of this plate. You should be able to slide it straight out to the right, but if not, it's because the bottom left attachment has been "modified." If so:
Once you have the main plate surrounding the platter off, you'll reveal a screw that fastens a brass "fork" that is holding one corner of the smaller plate. You'll see this screw just to the left of the bottom left corner of the plate.
Undo this screw (avoiding to drop it into the works), and pull free the brass fork. The plate is now loose at this corner, and you can work it free from the pins holding on the side closest to the right hand edge of the turntable. You might want to take it off during inspection before you begin your trip home.
Place something around the arms to prevent them from being able to move about during transport. On my previous BG4000 I used bubble-wrap around the arms, with a section between them at the width of their separation. If the person you're buying from is a stickler, you might find they've kept the original arm-lock.
