There are several approaches to dealing with narcissism, but therapy typically involves these essential steps:

identifying existing defense mechanisms
exploring reasons behind these coping methods
learning and practicing new patterns of behavior
exploring how behaviors affect others
examining connections between their internal voice and their treatment of others

The key to lasting progress often lies in:

helping someone see how positive change can benefit them helping them explore causes of narcissistic defenses without criticism or judgment offering validation
encouraging self-forgiveness and self-compassion to manage shame and vulnerability.