Stand with feet hip-distance apart and raise the right leg, flexing the right ankle and pushing the hips back.
Lower the body while keeping the right leg raised (a squat with one leg).
Hold and then return to standing to complete the rep. You can use a bench to squat/sit on to work your way toward doing the single-leg squat if needed.
Keep the knees behind the toes and the heels firmly on the floor.