I've seen cranes used, but that is the least likely way. Things can be taken apart and re-assembled; removing the legs is common. There are freight elevators and stairs. Just ask a moving company; I used to work in one for a while. Or give the people a call, or have your friend ask. I haven't bumped into too many people who would consider it a secret.

There's a freight elevator besides the public one.

They have freight elevators that you didn't see. These are usually about 3-4x the size of a normal elevator.

how did Eric Claptons kid die....FOCUS....

I went to a party last night in a NYC building where the apartment was on the forty-sixth floor. Something I kept thinking about was how the hell they managed to get furniture into the place. Yes, there's an elevator, but it wasn't huge. Meanwhile this guy had a TV the size of an entire wall, and a goddamn piano. So how do they get huge furniture into sky scrapers?