One thing you can do is tip the piano and put it on a dolly.
To do it right you need a dolly and three guys of average strength, and a fourth person to position the dolly.
One person needs to be the leader. This is teamwork.
A blanket should be placed beneath the bottom edge of the side of the piano that’s going to remain on the floor and bear the weight of the piano.
If the piano has removable legs remove them. They should just twist off. They’re not designed to bear the weight of a tipped piano.
have one guy stand at one end of the piano with the blanket underneath. This person will stabilize the piano.
The leader says “lift with your legs, not your back”
Have the two other guys at the other end lift their end of the piano. The leader goes “1, 2, 3, lift!” or some such thing. Coordination of power is extremely important here.
What you do now is have the 4th person put the dolly underneath the piano (at the halfway point), and tilt the dolly up so it’s flush against the bottom of the piano. Piano and dolly should both be tipped similarly. Two of the dolly’s wheels will be off the ground.
What happens now is that the piano is lowered, while the dolly person is holding the dolly in place, and the stabilizing person basically spots it so it doesn’t go rolling away from the people lowering it. If the piano rolls away from the lifters a back injury is likely.
Now you have a piano on a dolly ready to roll!
Like Zeldar, if I have to move something heavy on my hardwood floor, I’ll just tip it or rock it and throw towels under the corners and slide it around.
If it’s one those big old center-cut oak jobs that are as heavy as granite you should probably just call a piano mover.