Howto change google map api in metabox wordpress

if our wordpress metabox dont provide field to change google map api, we should change it manualy :

1. open htdocs\wordpress\wp-content\plugins\meta-box\inc\fields\map.php
2. search this line :
   // Users should overwrite this key with their own key.
3. change the ‘api_key’ line below it with your google map api :
   example : ‘api_key’       => ‘AIzaSyC1mUh87SGFyf133tpZQJa-s96p0tgnraQ’,
   change to : ‘api_key’       => ‘AIzaSy123445_1235ffdfd’,
   (change with your own api, how get it you can read it here)
4. Done