The doors they are taking off are the house doors.

Pianos (upright) DO have feet, and they do usually have "handles" at the back, so you can strain your back lifting the buggers - actually they are for stability and guidance as you are supposed to use "piano straps" to carry the thing.

These are 2-3 inch wide thick leather straps about 20 feet or longer - you use two sets - one with a guy at each end of the piano. They go over a shoulder and under the base of the beast. Real furniture movers in the 1960's used to always have them - they seem to have fallen out of use over the years. You used to able to hire them if you were clever enough to KNOW what you were doing when you moved a piano without paying the professionals to do it....

Robin