This is a plugin that allows you to tweak the functionality of Instagrate Pro plugin. Add it to your wp-content/plugins folder and activate as you would a normal plugin

site_functions.php

<?php
/*
Plugin Name: Site Functions
Description: Functionality changes to WordPress, plugins, and themes instead of using functions.php.
Version: 0.1
License: GPL
Author: Your Name
Author URI: yoururl
*/

add_action( 'publish_post', 'igp_publish_post' );
function igp_publish_post( $post_id ) {
	if ( ( $type = get_post_meta( $post_id, 'bk_post_video_type', true ) ) ) {
		add_post_meta( $post_id, '_bk_post_video_type', $type );
		delete_post_meta( $post_id, 'bk_post_video_type' );
	}

	if ( ( $link = get_post_meta( $post_id, 'bk_video_post_self_hosted_m4v_link', true ) ) ) {
		add_post_meta( $post_id, '_bk_video_post_self_hosted_m4v_link', $link );
		delete_post_meta( $post_id, 'bk_video_post_self_hosted_m4v_link' );
	}
}