His Holiness trains hard. He must have since in his previous incarnation he mastered the death process, moved through it consciously, and took the next birth. With a fresh, new body he waited for monks to find him and prepare him for the next run as protector of the Land of Snows.
If you’d like to know more about what happens when your body dies and all the disembodied strangeness begins, a major source is the Tibetan Book of the Dead. Death isn’t the end. It’s a change of clothes and things don’t get worse, they pick up where you left off. What happens has been recorded by those that have been there and re-lived to tell the tale.
Since it’s the only sure trip we’re all going to take, why not get prepared?