Rushing could easily damage the car.
A lot of supercar manufacturers don't spend much time making removable roofs easy to take off and put on. The mechanisms are very often afterthoughts, and Pagani is certainly not unique in offering a car with a complicated roof. Just the same, this is a whole new level of complicated, as several of the fasteners are not readily accessible on the Zonda 760 Roadster. Not only that, but removing the roof without damaging other parts of the car is tricky.
It is definitely a two-man job, and you can see it being performed here.