A trash compactor is deceptively heavy because of the dense compacting ram and motor inside. Empty it, cut the power, and secure the drawer and ram so nothing shifts, since the moving mechanism is the part that can pinch or jam.
Pro tip: Give the interior a wipe with a disinfectant before packing so it does not develop odor in storage.
Watch out: The compacting drawer and ram can pinch fingers. Tape the drawer shut and keep hands clear of the mechanism.