The ego tries to remake the world according to its own self-perceptions. The ego will expect others to be friends with the same people we perceive as good and stay away from folks we see as bad. The ego will try to convince others of religious, political or other viewpoints. The arrogant ego will try to force others to be complimentary. The negative ego will see every bump in life's road as proof of their unworthiness.
Perhaps killing the ego is more along the lines of killing the desire to create 'proof' of personal perceptions. Perhaps it is closer to killing the need to force the world to fit within our parameters.
I know, for example, that my own ego - or nafs - is intent on being the greatest genius in the room, and spends its existence in bitter, ranting anger that the Real World of Horrible Jobs doesn't conform to its desires, bowing down to acknowledge its mistress.