With patience and love ! Toddlers at that age don’t have the ability to express their emotions properly yet, let alone understand these emotions and controling them. You can help by modeling, help him to verbalise and find different ways to express. A big hug, counting till ten, a glass of water, deep belly breaths are all things you can teach him. Watching video about feelings on YouTube kids and doing feelings games and puzzles can be helpful too

My son is 2 and a bit and also does this, so I kow how you feel, it’s so embarrassing at the shops /playground etc when it happens, so I am following this post for advice too lol