There are ways to achieve immortality, but every single one of them involves dying.You can realize the deathless nature of your consciousness, which will apparently free you from samsara. When you die, you will dwell with a limitless and unrestricted awareness, at home in the nature of your mind. This is what they say, although we can't know - but you can know the deathless nature of your consciousness in this life, even if what that entails in the hereafter is indeterminate.You can also do phowa to project your mind to an immortal realm at the moment of death. For instance, thinking of some Bodhisattva and going to their realm, or thinking of some version of Jesus and going to a Christian heaven variant.Another method is simply doing nothing, since you will either reincarnate or go to some heaven or hell realm. You might not remain as you are now, but you will never be annihilated.