If you can't put it back in the original packaging, get it off the stand and firmly down on a proper pallet, bubble and shrink wrapped. Keep some low level ink carts in it, and keep it level. Most importantly, insure it for the full value and make sure the insurance gives you a chance to properly test it once it is delivered and setup. After it arrives, give it a day for ink to settle.
Also, run a nozzle check before you pack it and do cleans if needed.
If either of the maintenance boxes are fairly full, pull them out and check that they're not sloshing around (if so, put new ones in). Generally it will be fine unless you've just done a lot of printing or cleaning.