Here are three ways you can help your partner to let go of their anger (or use the same techniques to work on your own anger issues):
1. If you find that your partner's anger triggers your anger, recognise that this is part of a power struggle - you are both trying to have your needs met. Remember that somebody who is angry is hurting inside. Consciously refuse to fight, and (difficult as it is!) show them empathy and compassion. This will defuse the anger and allow you to help your partner.
2. If your partner is getting angry rather than feeling their pain, what might be at the root of this? What aspect of their past life could have left them with difficult feelings that they would rather not experience? Help them understand and heal these.
3. All relationships will have moments of anger, but these incidents can be turned to your advantage if you can use them to build a better partnership. Once any anger has subsided, always talk to each other about why you felt as you did and work with each other to heal the underlying issues and insecurities.
There are many Anger Management courses available if you (or your partner) would like to work in a group to understand and let anger go - find one that is local to you.