A curio cabinet is almost all glass, so it is one of the most fragile items in a home. Emptying it, pulling every glass shelf, and immobilizing the doors is essential before it moves an inch.
Pro tip: The small metal or plastic shelf clips are easy to lose; bag them the moment you remove a shelf.
Watch out: A curio cabinet has glass on nearly every side including a mirrored back; treat the whole piece as breakable, not just the shelves.