Facing front, execute a two-count riff on your right foot: Brush the ball of your foot against the floor--or touch the ball of your foot against the floor, depending on which style your instructor prefers--and then dig your heel into the floor and to the front.
Do a switch pullback. Your right heel is dug into the floor, but there is no weight on the heel. Your weight is on your left foot. Bend your left leg and spring up into the air, executing a back brush or spank, and then land on your right heel--not on the ball of your right foot but the heel. This is a very advanced step. You may want to hold onto a dance barre for support and balance when first attempting this step.
Step down on your left foot to the back.
Repeat all of the above steps: Pull your right foot back in and underneath of you, do a forward brush followed by a heel dig. Do the switching pullback. Spring off your left foot and execute a back brush, landing on the heel of your right foot. Quickly step down on your left foot to the back.
Remember that a pullback becomes a switching pullback (or swap or graboff pullback) when you land on the opposite foot, as is the case in this step. However, you aren't normally required to land on your heel.