Place the Reebok Step upside down on the floor.
Pull out the riser from the base of the step.
Hold the riser with the flat end facing up and slide it into the step deck to make a six-inch step.
Turn the step sideways. If you have done it correctly, the step and riser will make an interlocked zig-zag pattern.
Adjust the step by removing the riser and sliding it into the next highest notch on the step. This gives you an eight-inch step.
Turn the step sideways and check the fit. The eight inch set-up has one interlocking zig-zag shape.
Remove the riser to adjust the step to the highest, 10-inch height.
Turn the riser 180 degrees so the smaller end is pointing inwards.
Push the riser into the bottom of the step creating a C-shape.
Turn the step face-up and push down to ensure the riser is fixed tightly into the step.