Check out a short guide on how to move the piano correctly:

Get the help of moving companies with storage options – they will be able to safely move this musical instrument up or down the stairs. The sheer size, heavy weight, and indistinct center of gravity make the piano very dangerous to move by people who have never done it before.
If you need to take the piano up or down the stairs, learn all the information about it. What matters is the age of the flights of stairs, design and structure. In some cases, steps may not support the weight of a musical instrument (around 300 kg), coupled with four or five loaders. So, you have to give up the idea of moving the piano. It is better to know all the nuances in advance than to risk the life and health of people.
Do not be too lazy to plan and study the route. Don’t forget to measure any doors you come across to make sure the piano will fit right through them.
It’s also worth looking into how the doors of the truck you’ll be transporting the piano open in advance, as well as thinking about ways to load it.
When thinking about how to transport your piano, take our advice and invite one mover for every 45 kg of cargo.
Be sure to check that each worker is wearing rubberized work gloves, and special support belts that prevent stretching of the back muscles will not interfere.
The musical instrument must be prepared for transportation. Because of its heavy weight and bulkiness, you will need a wide cart. Close and secure all covers of the piano, wrap the instrument in a blanket, tying it with a ribbon, then bring a cart to one end of the piano, and with the help of assistants tilt it onto it.
It is important that there are more people on the side of the musical instrument that rests on the trolley. This is necessary to support the weight of the piano, as it will lean back, and by supporting it from the side, the movers will be able to maintain balance. This point is essential for this kind of instruments because of their great weight.
Don’t let gravity get in the way of your plans, with maximum effort gently push the piano to the end of the cart.
If you’re unlucky and the piano on the trolley won’t fit in the doorway, you’ll have to make several passes to get it through without the trolley. Having overcome this section, you can again put the musical instrument on the trolley, the main thing is to make sure that it is level and stable.
Remember that the correct way to lift weights is to squat down with a flat back and lift the object with the strength of your legs. Make sure your assistants are aware of this technique.
If during the transfer process you feel that the piano is unstable, you must immediately notify others and set up the instrument properly. Move the cart, swap people if necessary, and try again.
When thinking about moving a piano, keep in mind that it needs to be supported from below. If you decide to do it yourself, without seeking the help of professionals, then remember that a tool aimed down will put more pressure on the stairs compared to a flat surface.
Place most of your assistants at the part of the tool that is at the bottom, holding it. It is very important that each person behind the piano has enough space to step aside if necessary. After all, if someone loses balance, the instrument may fall. Your task is to make sure that everyone has the opportunity to step aside if one of the assistants, for example, stumbles.

Another important rule to keep in mind when deciding how to move a piano is to move as slowly as possible. Even when moving on a flat surface, you must constantly stop to recuperate and use a different grip. Working slowly and methodically will keep you in control from start to finish, reducing the chance of accidents.