Start off by removing the pod from the main body/battery assembly. Once apart you can now remove the black mouth piece from the pod.
You will see three holes on top of the pod once the mouthpiece is removed. The center hole is the chimney of the coil. Do not fill from the center hole. The two outer holes are for refilling.
Simply fill to the desired level and then snap the mouth piece back on top. The stubby tip from from some e-juice bottles should work, otherwise a small plastic syringe may be used.
Once the pod is assembled you can install it back on the battery. Once securely installed the LED will flash to indicates its made contact.