What should a wise man do if his Evil Impulse tempts him to hate his fellow Jew? He should directly rebuke it and say to it:
"Why do you always chase me and tempt me to hate my fellow man? When you put hatred into my heart, it is as if you have put pork into my mouth."
"You goad me to hate him, but I cannot see why I should do this. It is clear to me that what he does is not his fault. Yet you would have me suspect those above suspicion."
"Actually, it is you I really resent. I hate you fiercely because you wish to make me hate my fellow Jew. You are a worse enemy than he is, for you cause me to be hated and despised by G-d."
"The Torah says, 'Do not hate your brother in your heart.' If you had your way, I would be breaking this commandment with every passing second."
"I already know you for a liar. Whenever I want to do a good deed, you present me with arguments for why I should not do so. Every time I want to avoid a sin, you come up with claims to show me that what I thought was forbidden is really permitted."
"Thanks to G-d's kindness, I have overcome you many times. If not for that, you would have caused me to sink deep in sin long ago."
"After long experience, and after examining my bad deeds, I am convinced that it was you who led me to sin. The Torah says, 'Sin lusts after you' (Bereishis 4:7). Rashi understands this to mean that man's Evil Impulse constantly desires to make him stumble."
"Starting today, I shall never again resent or hate my fellow Jew."Whoever thinks like this, G-d will bless him in all that he does. If a person accepts these words upon himself, then he can be sure that he will not be trapped by his Evil Impulse, and his hatred will leave his heart. These words shall bless him and cancel out his former thoughts.
Source: Chofetz Chaim on Ahavas Yisrael, Chapter 4