To properly package it you MUST remove the platter from the plinth, and wrap it seperately. If it has a removable sub platter, that should go too.
Depending on the design of the tonearm, this should be removed also, HOWEVER, if not ensure that it's tied down to the rest position so it cannot move. Also be certain that nothing will move and hit or sit against it.
I am not sure about this table, does it have transit screws? I am quite certain that it's a suspended design, so you will need to ensure that the suspended portion is stable.
Alot of guys double box in this situation, better safe than sorry. Don't give your buyer any reason to bring something back on you. Photograph everything as you pack it, and in it's final stage before posting. Use a digital camera so the pics are time stamped.