At 8 p.m. on Monday night, the ground floor of the Solomon R. Guggenheim Museum looked a little like the base camp for a mountaineering expedition. Wiry young men sorted through piles of cables and hoists, their pants jingling with various pieces of climbing equipment. But the evening’s goal was not to scale Mount Everest or K2. It was to put in place a portion of the artist Cai Guo-Qiang’s “Inopportune: Stage One,” a highlight of the upcoming retrospective, “Cai Guo-Qiang: I Want to Believe.”

One of the most technically challenging works the museum has ever installed, “Inopportune: Stage One,” when complete, will consist of nine white cars, pierced with blinking light rods, dangling one above another in the museum’s rotunda. In a scale model, the cars descend in a spiral and appear to tumble over one another; the effect, with the blinking light rods, is of a single car exploding and turning somersaults as it falls through space.

The installation, which began on Friday night and will continue each night, between 6 p.m. and 2 a.m., until mid-February, is the result of a year of planning with the artist and with structural engineers. Early on, the museum determined that hoisting the cars with pulleys, which people could do from the ground, would put too much pressure on the ceiling. Although the cars have been stripped of almost everything except their hub caps, both to reduce weight and to eliminate the risk of their dripping oil or brake fluid onto people below, they still weigh about 1,200 pounds each. So one of the museum’s staff members suggested instead using rope access — essentially, people who would hang from the ceiling and hoist the cars up from there.

This was why, on Monday evening, Frédéric Audette and Franck Le Gleut, two former rock climbers from Montreal, were preparing to loft themselves into the rafters. They had already lifted the first two cars over the weekend; tonight’s plan was to lift the third. Because lifting each car is a four-person job, Mr. Audette and Mr. Le Gleut, who run a company called Vertika, had trained two of the Guggenheim staff in rope access. Another staff member, a slight, pretty young woman named Stardust Atkeson, was already trained; it was in fact she who recommended Vertika, as she had worked with Mr. Audette on an earlier rope access job.

Rope access is typically used for industrial inspection and maintenance. “Usually, we’re wearing Tyvek and full-face masks,” Mr. Audette said. For the Guggenheim job, they were in T-shirts.

While he and Mr. Le Gleut prepared their equipment down below, Mr. Cai’s technical director, Tatsumi Masatoshi, was up in one of the cars, installing the light rods. According to his colleagues, Mr. Tatsumi had been working almost 24-hour shifts, frequently neglecting to eat. On Sunday, as he worked in the top car, he would occasionally disappear from view for long periods of time, and one of the museum’s staff would have to knock on the hood to make sure he hadn’t fallen asleep.

After Mr. Tatsumi descended and was hustled off to eat and sleep, the rope-access crew took their places. From starting points on the museum’s top ramp, Mr. Audette, Mr. Le Gleut, and their two students lifted themselves up by anchors on the edge of the rotunda. They sat on little seats, and each gripped a hand hoist attached to a cable. The cable in turn was attached, far below, to the car number three, which was resting upside-down in a piece of equipment known as an “Auto Twirler” — essentially, a kind of car rotisserie. Over his walkie-talkie, the museum’s chief fabricator, Christopher George, gave the command to start hoisting, and the men began to pump vigorously. Ever few minutes, Mr. George would tell them to stop, and would check the car’s alignment. Sometimes he would tell one or two men to hoist alone, to lift one end of the car higher or move the car further in one direction. With their scale model, Mr. George and his staff had determined exactly how the cars had to be lifted to avoid swinging and hitting anything, such as the fountain on the ground floor.

Slowly, over the course of an hour and a half, the four men lifted the car into position. Ms. Atkeson had taken the night off because of a sore elbow, but she stood on the ramp and offered moral support. When the car was in place and the man finally let themselves down onto the ramp, Mr. George breathed a visible sigh of relief. Asked later how “Inopportune” compares with the other works he has fabricated over the years, he said, “It’s one of the most challenging and exciting.”