Stand up straight with a step positioned to one side.
Hold a weight in each hand.
Lift your leg furthest from the step off the floor, and cross it over the front of your stance leg.
Place this foot on the step and push your weight through your stance leg to step-up onto the step.
Bring your back leg round and place it onto the other side of the step.
Step your first leg across your original stance leg again to step down onto the floor.
Finally, bring your remaining leg down onto the floor.
Repeat the movement in the other direction, moving the leg furthest from the step across the front of the stance leg.
Step onto the step with this leg.
Bring the grounded leg up and across behind the first leg.
Finally step down onto the original side of the step moving your first leg across the second.