Here is an excellent prayer:
Lower my vengeance, my anger and my hatred,
and banish my wicked thoughts from me;
send down a drop from heaven of Your Holy Spirit
to vanquish this heart of rock of mine.
let our memory
provide no shelter
for the grievance agains another.
let our heart
provide no harbor
for hatred of another.
let our tongue
be no accomplice
in the judgement of a brother.