The kidneys are located on the both sides of the Mingmen. The Mingmen point is located between the second and third lumbar vertebrae. However, for a broader sense, Mingmen is referred to an area around the Mingmen point, including the area between the kidneys. 

Kidneys, according to the Chinese Medicine, are very important organs. Some qigong grandmasters, including Chen Xin, believes that chi is originated from the kidneys. Even though ChiLel qigong does not follow this theory, kidneys are nonetheless required special attention in order to facilitate one's healing.  Since kidneys don't move by themselves, we massage them through the movement of the Mingmen area. Because most beginners have stiff lower back, it is very difficult for them to move the lumbar vertebrae. Most of time they think they are moving the lumbar but in fact they are moving their thoracic vertebrae! 

A good way to begin to move your kidneys is to be aware of the lumbar vertebrae, especially the second and the third. Kidney Beach Ball Gong  is a simple way for beginners: Sit on a chair with a beach ball (size of a soccer ball) in between (refer to the above pictures). Press the ball from inside the kidney area towards the lumbar vertebrae (second and third) and then release. Repeat for five minutes or more. 

You can proceed to do the entire form of  Lift Chi Up and Pour Chi Down Method with a beach ball behind your lumbar vertebrae. For the more advanced student, you may want to do the Body & Mind Method with it.