What this is
There's a shift some people have, once, that changes how experience is structured from then on. Zen calls it kensho. Others call it awakening, or seeing through the self. Strip the names off and it's this: the sense that there's a you in here, behind the eyes, that everything is happening to — turns out to be a construction. Not a bad one; the mind builds it from a felt location, a sense of ownership, and a line between inside and outside, and it does useful work. But it's a model, not a thing, and it can be seen as a model. When it is, experience keeps going exactly as before, with nobody at the center of it. The shift is that seeing. Nothing is added; one assumption stops being made.
No beliefs are required for this, and none are offered here. It isn't a religious claim or a lifestyle. It's closer to an optical illusion resolving — once you've seen the second image, you can't unsee it, and you didn't need to believe anything to see it. The traditions found this first and kept the best instructions, so their words are used where they're the clearest. That's all the borrowing there is.
This isn't an introduction to the idea. It assumes you already know the idea, probably know it too well, and haven't had the shift. Knowing isn't the problem. Looking is. What follows is how to look.