A person who practices Tibetan yoga is seeking a higher rebirth or absorption in God. While an opportunity to achieve that exists shortly after the onset of death, the principal use of The Tibetan Book of the Dead is to show you how to achieve it in your current lifetime without having to die. This is called “The Short Path” and is what Rama taught in his Tibetan incarnations. It's a way to go through the equivalent of many incarnations in one lifetime. It's done by continually dissolving your old personality and creating a new one. Listen to Rama explain how it works.
Talk 11 of 28 in the Lakshmi Series.