Jing-to-Light transformation
The Clear Light has a natural resonance with the bindus.
* a primer on the integration of Concentration, Openness, and Light *
Introduction
This essay is about a central process that is pivotal. Many different practice methods, across traditions, are pieces that lead to, and are in support of, this process. It's important. Once you understand this process, many other things will sort of line up and make sense. It takes a while to soak in. Just take a swing at studying this, put it in your pocket and come back to it occasionally. It's helpful to know that this is where things are headed; there are various practical implications all along the way.
This essay is about the last phase of a three-phase process:
1. Activate the centers
2. Blend their energies
* 3. Resolve inside/outside into non-duality through the deep-centers *
I'm going to state this first very briefly in two short lines with pictures. Then I'll go over it again in more detail.
Short version
(two steps)
1. Concentrate in the deep-center(s) and refine.

2. Refinement culminates in concentration integrating with Openness.

Detail
(same steps)In each deep-center (at least in the power, love, wisdom centers) there is an important item of subtle anatomy called a "bindu" (translated as "drop", "dot", "source-point", "seed"). A bindu is small (said to be the size of a mustard seed) and has a special resonance with Vast Light. Typical of the deep-center, it is the unification of concentration and openness.

A number of prominent people have said that jing, past a certain point, cannot be saved; it must be transformed. Transformed into what?
In practice, jing is transformed into Light.
In the beginning, this is felt or seen as the gentle radiance of a center, which transforms and absorbs denser energies (including jing) towards the deep-center. The later stage of this is that the light becomes more focused, stabilized, within the deep-center - through stillness and concentration. Bursts of light into the center's perimeter are gently brought back to the deep-center, where the light of the bindu + jing resolves into, unifies with a less personal, more universal, Vast Light. Light without form or edges. This Luminous Ground suffuses and purifies.
The process of :
Bringing one's expression of personal out-flowing attention inward, focusing on the radiance, stabilizing in the deep-center, and - through concentration - subsuming to Vast Light,
.. is referred to in The Secret of the Golden Flower by the key phrase, "turning the light around". "The secret of the golden flower" itself refers to Vast Light hidden within a center's deep-center.

Finding, and yielding to, this undifferentiated Vast Light through stabilized concentration (stillness) in one's own deep-center is a primary gateway through which many of the more important classical progressions occur.
~ Quote ~
The golden flower is light. What color is light? It is symbolized by the golden flower, which [in Chinese characters] also conceals [the words] "one light" within. This is the absolutely unified real energy of celestial immortals; this what is meant by the saying, "The lead in the homeland of water is just one flavor."
- from The Secret of the Golden Flower, pg 10
NOTES
Three Centers, the Central Vessel.
In my experience, the above process occurs most easily when its employed in (at least) the three main centers (power, love, wisdom) in concert, and in support of each other by sharing through the central vessel.
Gradual progress.
The illumination of a bindu is often quite gradual. Storing refined energy in the deep-center over a substantial period of time, and a slight shift of attention of "looking for the light", triggers the illumination of the area and - eventually - of the bindu. Recognizing the connection of the bindu with Vast Light might happen some considerable time after that. My point is that the above essay puts, very concisely, what is often a considerable course of work.
Stillness.
Stillness is prerequisite to the processes of the deep-center, to even finding the deep-center, really. Probably, for most of us, there are some days when physical, emotions, etc., are ruffled, and obscure the way perhaps more than another day. Again, no worries. Gradual progress.
This process is also represented by the symbol for this site and briefly explained in the Overview: