Once we all realised that he didn't want to be angry it got a lot easier for everyone. We gave him words and guidance to let him analyse his anger, helped him to try different means of coping with his feelings and then incentives to apply those tools.
BTW StackExchange's parenting community[0] is a good place to find answers to issues like this.
What incentives worked for you? We've tried the points/sticker chart thing without any luck (allowing him to redeem his points for audio books, tv shows, treats, and even Dave and Buster's if he saved up a lot).
We had a chart of 7 faces which could be happy or sad, one per day for a week, that he fills in at the end of each day. He gets a warning when he first starts to act up then a sad face if he carries on. All smiley faces means a small toy at the weekend.
Filling in the chart some long time after the behaviour was important as it allowed for calm(er) reflection on the consequences of bad behaviour.
It took a couple of weeks to see an improvement but over all has worked really well for us.