I'm going to inform my really close friend that he should change his attitude or else everyone else would be fed up with him and he wouldn't have any more friends
What changes do you think your friend should make?
he could be a little more humble
Humility is a hard trait to build, and you coming down on your friend to change his behaviour is critical and not constructive. Keep your criticism to yourself and work on your own humility.
It's not my fault that he's a jerk to everyone.
I get you are frustrated with his attitude, but you don't really know his situation and why he acts out. Have you thought about he would feel if one of his friends suddenly snapped on him? He might not take it well and I believe it's best to just calmly talk about it.