The key to loading or unloading these boxes, is to remove all of the drawers first to make the box as light as possible! My son and I unloaded both of my HF 56” boxes that way, and it wasn’t bad at all. Removed the drawers, then my Son on one side, and I on the other, lowered one end of the box to the ground. Then the same with the other end. And this being lowered from my ‘01 Tacoma 4WD.
Did the same procedure in reverse when we returned one of my 56’s for the matching better number box.
Edit: It’s best to remove the carton and pallet from the box at the store. Removing the box from the pallet while in the bed of the truck is a real PITA! Plus, this way you can inspect for damage before leaving the store.