Set all WP users name to regular case

set_wp_user_names_to_normal_case.php

<?php

// Place this in Home directory
define( 'WP_USE_THEMES', false );
require( 'wp-blog-header.php' );

// Security Check
if ( current_user_can( 'manage_options' ) === false )
	wp_die();

$users =  get_users();
foreach ($users as $user) {
	$first_name = get_user_meta( $user->ID, 'first_name', true );
	$last_name = get_user_meta( $user->ID, 'last_name', true );

	$first_name_new = mb_convert_case($first_name, MB_CASE_TITLE, "UTF-8");
	$last_name_new = mb_convert_case($last_name, MB_CASE_TITLE, "UTF-8");

	echo '<p>' . $last_name . ' ' . $first_name  . '<br/>';
	echo  $last_name_new . ' ' . $first_name_new . '</p>';
  
  // Append '?update' to the url to perform changes
	if ( isset( $_GET["update"] ) ) {
		update_user_meta( $user->ID, 'first_name', $first_name_new );
		update_user_meta( $user->ID, 'last_name', $last_name_new );
	}
}