How to override existing plugin action with new action

I’m using a plugin. It has an action like this.

add_action('publish_post', 'old_action');
function old_action($pid) {
    "code goes here"
    }
}

I’m writing a module for this plugin. So i need to override that old action function with my new action function.

This is my new function.

function new_action($pid) {
      "code goes here"
        }
    }

I want to replace that old_action function with my new_action function using hooks. Can anyone help me?

Thanks

You can use the remove_action() function, like this:

remove_action('publish_post', 'old_action');
add_action('publish_post', 'new_action');

It’s important to note that if the old_action was added with a priority parameter, you must add that to the remove_action call, otherwise it will fail to remove it. There are other implications if the old_action was added within a class. See here for more info.