The process of reversal is based on ancient paradigms of cosmic manifestation, for the creation of universes, our world, mankind. If we look at these paradigms metaphysically, we can reverse the path through intentional physical and internal practices to return to the Source. This is the process of yoga, tantra, Daoism, and many related shamanic and martial practices.
What I don't advocate is getting bogged down in the original paradigms themselves. For lack of a better way to say it, these are metaphorical explications of a process that is inexplicable. In the end, there are no words to adequately describe this process, but ancient sages of various cultures have found tools of language to help make it clearer, as long as you understand they are in the end poetic in nature. For our purposes, that matters as we reverse the process, much more than understanding the original process. We don't need to understand the process of manifestation as much as we need to understand the process of awakening. In short, you don't need to understand nuclear engineering to benefit from the electricity generated from a nuclear power plant. If you do want to understand the engineering, that's OK too. It's just not the focus of this teaching.
Does any of this really matter? Well no, not really. We can and should just live our lives as they unfold. Again, I refer to the nuclear engineering comparison above. However, it is possible to live life on a different level with better health, clearer thinking, higher, clarified energy levels, with spiritual understanding. To that end, if one is interested in the benefits of esoteric Daoist or yogic practice, then this approach can be helpful. Below are two links describing different approaches to this process. Consider these: