Keeping your shoulders over your legs, and your back straight, drive up from the chair using strength from the hips and thighs to minimize the stress to your lower back.
Leaning way forward, extending legs then dragging upper body up using the lower back.
Squat down, keeping the back straight and the shoulders over the legs. Alternatively: staggered stance squat down, keeping the back straight and the shoulders over the legs. This may be helpful for your balance as you reach down.
Legs are straight, back is rounded with the shoulders way in front of the feet as you reach down, stressing the lower back.