How do I let go of pent up anger towards an ex?

An Ex is someone we still love, yet cannot say it every day. We feel it in our hearts, we know it in our minds, but we cannot act on it. I've found that forgiveness is always the best path, backed by gratefulness and thankfulness ... thankful that I shared part of my life with this person that I love. The thing is Love is indestructible. It may change form, it may seem as if it has left, and it may seem mysterious. Love, it's always there no matter how much hatred you think you have for your Ex, you always Love them. Always.

Let it out in words write it down burn it or ask someone if you can let it out on them but take no offence

Find someone else to talk to. Find something to do to take your mind off of them. Distract yourself by hanging out with new people.

Start by giving yourself permission to forgive yourself and then forgive him/her. Forgiveness is the key to a peaceful mind

Punch a pillow, or read a book. Just do something to get them off your mind. If you see them in the streets don’t get mad at them, just say “hey” or ignore them.

Do things that make you happy, got out with friends, scrapbooking etc. you can also take every photo of the 2 of you and everything he gave you and burn it so you don’t have any reminders of him.

Learn to forgive and move past the issues. Find new friends to associate with and new activities to keep your time occupied.

I used to do that. But, later I realized it's not healthy for me mentally and I need to make peace in order to move on.

From my personal experience is learning to take a step back take a deep breath and look at all of the good things and not so much on the bad. When I allow my anger to get the better of me it is simply because of the fact that I have been hurt knowing that this person wants nothing to do with me. So I have to learn to understand the good sides and not allow the pain to give me the false judgement

Key is acceptance. Accept that it's over. Accept that it was a mistake. Forgive yourself and you'll forgive your ex. You'll realize that the anger you hold towards yourself stems from an anger towards your own discretion.