If we think of a replacement engine of a car we are talking about operations hours. You have to disconnect all the supply lines of fuel, wiring… in addition to disengage from the engine of their anchors to replace it with another engine. A team of marines british came to a contest of records in which they claimed to be able to replace the car’s engine in less than a minute. The car should start up and go through 10 meters with the new engine and all of the marines aboard.
Is better than what you see for yourselves. A display of coordination impressive.