As anyone who's had to change a tire on the side of the road
can tell you, the first principal step is removing the flat tire from the car.
Within this first stage of the procedure, there are other actions involved,
such as placing blocks against the tires, assembling the jack, using the jack
to raise the car, and unscrewing the lug nuts holding the tire in place.
The second principal step is replacing the flat tire with a spare, and the
third step is lowering the car back to the ground.
The fourth step? Figuring out how you're going to get all that dirt
and grease off your hands!