A tower of steel had been built in the hallway, known as Picasso Alley, to guard against that possibility. Workers scampered up 10 tiers of scaffolding, helping to operate a 23-foot-long tube that was meant to roll up the curtain and haul it away for a cleaning, after which it would go to a new home at the New-York Historical Society.
But the specter of the unknown haunted the proceedings. What if, after 55 years of hanging vertically, the canvas didn’t want to curl? The workers could only guess at what awkward and ancient method had been used to affix the fabric to the top of the wall.
Mr. Zoufaly searched his past for an answer. He learned the art installation trade from James Lebron, the very man who had mounted “Le Tricorne” here. “He’s sitting on my shoulder, saying, ‘Think about what I would have done,’ ” Mr. Zoufaly said.
The arthritic grind of a chain link pulley echoed off the limestone walls. Ten gloved hands wrapped the bottom edge of canvas around the two-foot wide tube, which steadily rotated and ascended as it peeled the canvas away. Protective wrapping hung over the painting like a surgical curtain. Mr. Zoufaly made the first disquieting discovery: someone had used a desk stapler to bind the sides of the canvas to strips of Velcro. Peg Breen, president of the conservancy, placed a hand delicately on her chest and walked into a different room.
They had been working for seven hours. “You still with us?” Mr. Zoufaly asked a sleepy-eyed pulley operator. It was 7:30 a.m.
Mr. Zoufaly climbed a ladder, trying to discern his old mentor’s method as swirling dust dried his mouth. The diagnosis: The canvas was attached with hundreds of staples to two pieces of wood, which were stuck together using 19 stainless steel screws.
Soon after, with the help of wooden wedges hammered between the parallel anchors, the canvas came unhinged. It did not suffer a single tear. When it was rolled up on the tube, some workers rubbed it as though it were an ancient scroll (though its real heritage involves being among the headaches of New York real estate).
“I’m so proud of this Picasso,” Ms. Breen said. “It held up. It did a wonderful job.”
It left the Four Seasons without ever touching the floor.
A version of this article appears in print on Sept. 8, 2014, on Page A14 of the New York edition with the headline: After 55 Years in Vaunted Spot, a Picasso Is Persuaded to Curl