Supta = Supine/Recline,  Vajra = Diamond/Thunderbolt, Asana = Pose or Posture

Steps

Stage 1

1. Sit in vajrasana, spread your feet apart to sit between them, your toes should be pointing backward, and your feet  tops should be pressing onto the floor. And  hold your toes, or keep your hand behind your feet on the floor beside the hip, fingers pointing toward the front.
2. Exhale, slowly bend back, placing the right forearm and the elbow on the ground and then the left forearm and the elbow on the ground.
3. Place the head on the ground and then bring the hands on the side of the legs, if this is not possible, stretch your hands back above the head or keep your hands on the namaste pose over the chest.
4. Close the eyes and relax the body. Breathe deeply and slowly in the final position for 5 to 6 deep breaths.
5. Inhale and take the support of the elbows and the arms raise the head above the ground.
6. Repeat this process for 2 to 3 times.
7. Never leave the ultimate position by straightening the legs first, it will cause pain to the knee joints.
8. Finally, relax your body in Sasangasana for a few minutes to relieve all the stress in the spine.
9. If you are not able to do the normal supta vajrasana, you can practice Stage 2.

Stage 2

1. Sit in vajrasana, place the palms on the floor beside the hip, fingers pointing toward the front.
2. Exhale, slowly bend back, placing the right forearm and the elbow on the ground and then the left forearm and the elbow on the ground.
3. Place the top of the head on the ground while arching the back and place your hands on your thighs.
4. Try to keep the lower legs in contact with the floor. If necessary, separate the knees, close the eyes and relax the body. Breathe deeply and slowly in the final position for 10 to 30 sec, inhale, relax your arms and head.
5. Breathe in and by taking the support of the elbows and the arms raise the head above the ground.
6. Repeat this process for 2 to 3 times.
7. Finally, relax your body in Sasangasana for a few minutes to relieve all the stress in the spine.

Benefits 

1. Improves digestion.
2. Relieves sleeping disorders.
3. Many respiratory ailments can be treated by practicing this posture.
4. It relieves menstrual pain.
5. It stretches your ankles and also your abdomen.
6. It relaxes tendons, ligaments, and many smaller muscles in the knee.