Select your weight. Adjust seat, upper body pad and head pad. Sit in machine with back to upper body pad. Place your face on head pad. Grasp handholds lightly.
Start the forward flexion  from  the extended position. Using your head, press pad forward carefully and slowly. Hold flexed position briefly and then slowly return to starting position. Make sure that the weight does not touch down. Repeat until a full movement is no longer possible.

Important: Lower weight carefully during extension phase. Keep upper body straight and shoulder relaxed.