Why worry about getting the piano down, if you will only get a new one in a few years? It seemed like an impossbile task to get it up there, remember, and everything worked fine...you'll manage when the time comes. If you buy a new piano next time, just make a deal that the dealer takes the old one so then it's not your problem anymore
I worked at a pretty tough school 20 years ago. One lunch time a group of boys ripped apart a good quality piano and fed it though the first story window bit by bit. All that was left in the room was the harp with strings attached as it wouldn't fit through. They may also have left the inside label that said the piano was guarenteed to withstand all extremes of climate (there's some irony there). Ahh, halcyon days! So yes, it can be done.
Last I knew you loved your piano, now you want to dismember the thing.
I wouldn't play a Yamaha piano if somebody paid me.
I've spotted my next piano to go in the trailer, a "Schroeber" made in Chicago pre-WWII. 6' high, 400 lb, decent tone and very fast. $80 at Salvation Army. Will be perfect for Scott Joplin and JoAnne Castle imitations. Now if I can just find a ramp to get it in the back of the pickup- renting a truck with ramp would be more than the price of the piano.
When I want to buy something, I buy used if I can find anything. I drive my car full of tools to and from the country place once a year, and ride a 197?