edit: I had a really high dose of LSD about ten years ago and it really changed my perspective of what reality is made of. I feel like the filter of ego on the true reality of the universe is just a tiny slice of the full spectrum of what is possible/actually happening.
The observer in isolation is the act of observing observing itself, and as such it is featureless and, in a sense, outside of time. So, yeah, eternal life. The catch is that it's life in general, it has nothing to do with your everyday life.
I only know that stuff from Burroughs' The Western Lands, which is his take on a "book of the dead".
FWIW, this is a decent description of what I'm talking about: https://en.wikipedia.org/wiki/Ramana_Maharshi#Self
> Ramana considered the Self to be permanent and enduring, surviving physical death. "The sleep, dream and waking states are mere phenomena appearing on the Self," as is the "I"-thought. Our "true nature" is "simple Being, free from thoughts".
As I understand it from Burroughs, there are seven souls in the Egyptian theory. Three of them are eternal. Sort of like components of Ramana's Self: Ren (meaning, destiny), Sekem (energy, power) and Khu (guardian). Then there's Ba (emotion), Ka (the double) and Khaibit (memory). And Sekhu (remains). The only one left after ones death is Ka, which has the chance at eternity in the Western Lands.
Can't be done, not even in principle.
> how to prepare my observer for the dissolution of my own mind and body.
The observer is unaffected by death or birth. If you can give up attachment to the impermanent aspects of your being then death is a change not an ending.
(This is the whole point of human life, everything else is kind of a sideshow. Less than one in a thousand ever even think about this stuff, of those less than one in a thousand will take it seriously and seek. Which is really really sad, because the path, though narrow, is not particularly hard. Avoid BS, seek Truth with persistence and sincerity. Do it every day. Eternal life guaranteed or triple your money back!)