What is the Antidote for a Hateful Temperament? What kind of practices can one do to neutralise a hateful temperament? 

Can i please have specific techniques.Thank you.

Edit:

By temperament i mean a character or habit.
The solution is to use Metta (loving kindness). For canonical description of Metta, please see the Karaniya Metta Sutta, Metta Sutta and the Mettanisamsa Sutta.

Information on how to practise Metta can be found here and here. These are quite specific and written by Ven. Dhammarakkhita and Ven. Buddharakkhita. These are too long to quote here.

Hateful temperament is part of "ill will", one of the five hindrances (also here) to meditation and practice. Ajahn Brahmavamso explains in this essay:


  Ill will refers to the desire to punish, hurt or destroy. It includes
  sheer hatred of a person, or even a situation, and it can generate so
  much energy that it is both seductive and addictive. At the time, it
  always appears justified for such is its power that it easily corrupts
  our ability to judge fairly. It also includes ill will towards
  oneself, otherwise known as guilt, which denies oneself any
  possibility of happiness. In meditation, ill will can appear as
  dislike towards the meditation object itself, rejecting it so that
  one's attention is forced to wander elsewhere.
  
  The Lord Buddha likened ill will to being sick. Just as sickness
  denies one the freedom and happiness of health, so ill will denies one
  the freedom and happiness of peace.
  
  Ill will is overcome by applying Metta, loving kindness. When it is
  ill will towards a person, Metta teaches one to see more in that
  person than all that which hurts you, to understand why that person
  hurt you (often because they were hurting intensely themselves), and
  encourages one to put aside one's own pain to look with compassion on
  the other. But if this is more than one can do, Metta to oneself leads
  one to refuse to dwell in ill will to that person, so as to stop them
  from hurting you further with the memory of those deeds. Similarly, if
  it is ill will towards oneself, Metta sees more than one's own faults,
  can understand one's own faults, and finds the courage to forgive
  them, learn from their lesson and let them go.