Kneel down on the ground with your hands on a step or small box.
Keep your hands under your shoulders and knees under your hips.
Straighten one leg and then the other leg back behind you.
There should be a straight line from your head through to your heels.
Lift one hand off of the step and place it down on the ground then lift the other hand off the step and place it down on the ground.
Repeat this movement to take you back up onto the step.
Repeat this movement to take you off of the step again, but to the other side.
Make sure that throughout this movement you keep your back stable and your core engaged.