Use a stool/stepper of appropriate height
You can choose the height of the stepper based your comfort levels.
Start on top with both the feet in line with each other.
With your eyes looking straight ahead, take a big breath and extend one leg back to perform a step down.
Land softly on the ground and push yourself up with the heel of your leading front leg.
Get back to the starting position and repeat the movement.
While stepping down, make sure that the knee of your leading front leg is in line with the toe.