Tolle on Grievances

“A long-standing resentment is called a grievance. To carry a grievance is to be in a permanent state of “against,” and that is why grievances constitute a significant part of many people’s ego. Collective grievances can survive for centuries in the psyche of a nation or tribe and fuel a never-ending cycle of violence.
“A grievance is a strong negative emotion connected to an event in the sometimes distant past that is being kept alive by compulsive thinking, by retelling the story in the head or out loud of “what someone did to me” or “what someone did to us.” A grievance will also contaminate other areas of your life. For example, while you think about and feel your grievance, its negative emotional energy can distort your perception of an event that is happening in the present or influence the way in which you speak or behave toward someone in the present. One strong grievance is enough to contaminate large areas of your life and keep you in the grip of the ego.” —-Eckhart Tolle, A New Earth, 65
Grievances promote cancer.
Is is even possible to do away with the ego (the id, super-ego)? Do we meet the Buddha and kill the Buddha, or do we improve the Buddha?