hate is a very strong word... and banishign him an even stronger action to incur upon someone. Before going as far as using a banishing spell/ritual maybe try talking to him? IF its harrassment then inform someone and have him removed from your life either by your own means or by other means (i dont condone violence as the answer0 or maybe show him he cant get to you so he leaves you alone.
In all honesty this is all the support i can give you because i am unaware of the full situation your in but these areprobably the best methods to take.
I agree with JZSpellz. You should do this the regular way instead using a spell to fix your problem. And I would just use an influencing spell to just influence the person. Not banish him from the face of the Earth.
All spells have a price. Nothing comes easy or free. You think it's easier to use a spell, but it'd be in your better interest to do it like the others are saying. Not only that, if you're being fueled by hatred, you could get in over your head and things would go not quite how you imagined. Just my bit of advice.
Okay to everyone, banishing isnt bad. In fact most say to banish a person before binding them and binding does invade free will! Banishing is just gently removing them from you. A banishing spell that I did, when a woman was harassing me,
1 black candle
A Bible turned to Psalm 94
banish oil or olive oil
Carve the Divine names eel kanno taf into the candle and concentrate on the person and read the psalm. Let the candle burn for five minutes as you meditate upon the person.
Snuff it out and light it every night for 9 days.