Seriously though, without the original packaging this seems quite challenging. Try asking the dealer if they have one; maybe some customer wanted them to throw it away after delivery.
Else ask a moving company, they should be able to build a carton box for it.
In any case I recommend to ensure the shipment, plasma and LCD TVs are the one item that are most likely to break during transport. At least so I was told when I shipped mine to HK.