An upright piano weighs 300 to 800 pounds packed into a tall, narrow case that wants to tip forward the moment it is off balance. A piano board strapped to the back and at least three trained movers is the standard, safe way this actually gets done.
Pro tip: Ask movers to place felt or rubber cups under the piano's casters at the final spot; it protects flooring and keeps the piano from creeping when the lid is opened and closed over the years.
Watch out: Never move an upright piano with fewer than three people on stairs; the combination of 300 to 800 pounds and a narrow tipping base is one of the most common ways movers get seriously hurt.