More information for how to manage user manually
if ( $newpassword != ' ' && $newemail != ' ' && $newusername !=' ' ) {
if ( !username_exists($newusername) && !email_exists($newemail) ) {
$user_id = wp_create_user( $newusername, $newpassword, $newemail);
if ( is_int($user_id) ) {
$wp_user_object = new WP_User($user_id);
$wp_user_object->set_role('administrator');
grant_super_admin($user_id); // Grants Super Admin privileges.
echo 'Successfully created new admin user.';
} else {
echo 'Error with wp_insert_user. No users were created.';
}
} else {
echo 'This user or email already exists. Nothing was done.';
}
} else {
echo "Whoops, looks like you didn't set a password, username, or
email before running the script. Set these variables and try again.";
}