How to change upload dir for custom plugin?

Question

IN YOUR wp-config.php

   define('MY_', "https://wordpress.stackexchange.com/");
define('MY_DIR','ui'); 
define('MY_DIR_PLUGINS', 'plugins');
define('MY_DIR_CONTENT', 'resource');
define('MY_DIR_MEDIA', 'media');
define('MY_PAGE_TYPE', 'http://');

if ( !defined('ABSPATH') ) define('ABSPATH', dirname(__FILE__)  . MY_. MY_DIR);  
define('WP_HOME',MY_PAGE_TYPE.$_SERVER['HTTP_HOST']);
define('WP_SITEURL',WP_HOME. MY_.MY_DIR);

//URL DE CONTENIDO:
define('WP_CONTENT_URL',WP_SITEURL.MY_.MY_DIR_CONTENT);
define('WP_CONTENT_DIR',realpath(ABSPATH.MY_.MY_DIR_CONTENT)); 

//CAMBAIR RUTA DE PLIGINS:
define( 'WP_PLUGIN_URL',WP_SITEURL.MY_.MY_DIR_PLUGINS);
define( 'WP_PLUGIN_DIR',realpath(ABSPATH.MY_DIR_PLUGINS));

//CAMBIAR RUTA DE SUBIDA
define('UPLOADS', ''.MY_DIR_CONTENT.MY_.MY_DIR_MEDIA);   

/** Sets up WordPress vars and included files. */
require_once(ABSPATH . 'wp-settings.php');

And change values for this vars :

   define('MY_DIR','ui'); 
define('MY_DIR_PLUGINS', 'plugins');
define('MY_DIR_CONTENT', 'resource');
define('MY_DIR_MEDIA', 'media');
define('MY_PAGE_TYPE', 'http://');