The easiest way to complete a tough ritual, is to create a fake one that lies about the outcome. Then you just need to spread it and eventually someone else will complete it for you. Something along the lines of, "To be reborn, you must first die. To obtain immortality, you must prove your desire. Once every eclipse, an opportunity shall arrive. Where forest meets mountain, a clearing lies. Here the next divine shall arise."
Suddenly, a step as hard as a willing self sacrifice, will just complete itself.