I hate my ex best friend
I'm sad that you feel that way, but why do you think you hate him?
Everything that was good about the friendship came from our group of friends and me, and he hasn't contributed anything towards our friendship.
I think that sounds like something you should be talking through with him, not with me!  I hope you two can work out your issues.
Thanks!
If he is lacking in his efforts towards your friendship, then you should tell him. I would also suggest that you don't be disrespectful towards him or insult him, as he may not know that you need more from him with this friendship.