In the section on Removing Meta Boxes in Custom Meta Boxes,
it says wp-includes/edit-form-advanced.php,
but I can't find the corresponding file under wp-includes/.
To remove default meta boxes check the source code for the parameters used. The default add_meta_box() calls are made from wp-includes/edit-form-advanced.php.
I would appreciate it if you could check that.
Thank you in advance.