Stand with your back perpendicular to the flat bench.
Sit down on bench with hands at your sides.
Place feet on box or bench in front of you, so both legs are off the ground. Have a spotter place a barbell plate on your lap. Lower your body straight down slowly and press back up powerfully. Repeat this range of motion until all reps are completed. Have spotter remove plate, then bring feet down from the bench. Stand up and recover.