Try this (not tested, but should give you an idea):

<?php defined('BASEPATH') or exit('No direct script access allowed');
 
class Module_Blog extends Module {
 
    public $version = '2.0';
 
    public function info()
    {
        $info = array(
            'name' => array(
                'en' => 'Blog',
                'ar' => 'المدوّنة',
                'el' => 'Ιστολόγιο',
                'br' => 'Blog',
                'pl' => 'Blog',
                'he' => 'בלוג',
                'lt' => 'Blogas',
                'ru' => 'Блог',
                'zh' => '文章',
                'id' => 'Blog'
            ),
            'description' => array(
                'en' => 'Post blog entries.',
                'nl' => 'Post nieuwsartikelen en blogs op uw site.',
                'es' => 'Escribe entradas para los artículos y blog (web log).', #update translation
                'fr' => 'Envoyez de nouveaux posts et messages de blog.', #update translation
                'de' => 'Veröffentliche neue Artikel und Blog-Einträge', #update translation
                'pl' => 'Dodawaj nowe wpisy na blogu',
                'br' => 'Escrever publicações de blog',
                'zh' => '發表新聞訊息、部落格等文章。',
                'it' => 'Pubblica notizie e post per il blog.', #update translation
                'ru' => 'Управление записями блога.',
                'ar' => 'أنشر المقالات على مدوّنتك.',
                'cs' => 'Publikujte nové články a příspěvky na blog.', #update translation
                'sl' => 'Objavite blog prispevke',
                'fi' => 'Kirjoita uutisartikkeleita tai blogi artikkeleita.', #update translation
                'el' => 'Δημιουργήστε άρθρα και εγγραφές στο ιστολόγιο σας.',
                'he' => 'ניהול בלוג',
                'lt' => 'Rašykite naujienas bei blog\'o įrašus.',
                'da' => 'Skriv blogindlæg',
                'id' => 'Post entri blog'
            ),
            'frontend'    => TRUE,
            'backend'    => TRUE,
            'skip_xss'    => TRUE,
            'menu'        => 'content',
 
            'roles' => array(
                'put_live', 'edit_live', 'delete_live'
            ),
 
            'sections' => array(
                'posts' => array(
                    'name' => 'blog_posts_title',
                    'uri' => 'admin/blog',
                    'shortcuts' => array(
                        array(
                            'name' => 'blog_create_title',
                            'uri' => 'admin/blog/create',
                            'class' => 'add'
                        ),
                    ),
                ),
                /*'categories' => array(
                    'name' => 'cat_list_title',
                    'uri' => 'admin/blog/categories',
                    'shortcuts' => array(
                        array(
                            'name' => 'cat_create_title',
                            'uri' => 'admin/blog/categories/create',
                            'class' => 'add'
                        ),
                    ),
                ),*/
            ),
        );
 
        if ($this->current_user->group == 'admin') {
 
            $info['sections']['categories'] = array(
                'name' => 'cat_list_title',
                'uri' => 'admin/blog/categories',
                'shortcuts' => array(
                    array(
                        'name' => 'cat_create_title',
                        'uri' => 'admin/blog/categories/create',
                        'class' => 'add'
                    ),
                ),
            );
        }
 
        return $info;        
    }
 
    public function install()
    {
        $this->dbforge->drop_table('blog_categories');
        $this->dbforge->drop_table('blog');
 
        $blog_categories = "
            CREATE TABLE " . $this->db->dbprefix('blog_categories') . " (
              `id` int(11) NOT NULL auto_increment,
              `slug` varchar(20) collate utf8_unicode_ci NOT NULL default '',
              `title` varchar(20) collate utf8_unicode_ci NOT NULL default '',
              PRIMARY KEY  (`id`),
              UNIQUE KEY `slug - unique` (`slug`),
              UNIQUE KEY `title - unique` (`title`),
              KEY `slug - normal` (`slug`)
            ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci COMMENT='Blog Categories.';
        ";
 
        $blog = "
            CREATE TABLE " . $this->db->dbprefix('blog') . " (
              `id` int(11) NOT NULL auto_increment,
              `title` varchar(100) collate utf8_unicode_ci NOT NULL default '',
              `slug` varchar(100) collate utf8_unicode_ci NOT NULL default '',
              `category_id` int(11) NOT NULL,
              `attachment` varchar(255) collate utf8_unicode_ci NOT NULL default '',
              `intro` text collate utf8_unicode_ci NOT NULL,
              `body` text collate utf8_unicode_ci NOT NULL,
              `parsed` text collate utf8_unicode_ci NOT NULL,
              `keywords` varchar(32) NOT NULL default '',
              `author_id` int(11) NOT NULL default '0',
              `created_on` int(11) NOT NULL,
              `updated_on` int(11) NOT NULL default 0,
              `comments_enabled` INT(1)  NOT NULL default '1',
              `status` enum('draft','live') collate utf8_unicode_ci NOT NULL default 'draft',
              `type` set('html','markdown','wysiwyg-advanced','wysiwyg-simple') collate utf8_unicode_ci NOT NULL,
              PRIMARY KEY  (`id`),
              UNIQUE KEY `title` (`title`),
              KEY `category_id - normal` (`category_id`)
            ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci COMMENT='Blog posts.';
        ";
 
        if ($this->db->query($blog_categories) && $this->db->query($blog))
        {
            return TRUE;
        }
    }
 
    public function uninstall()
    {
        //it's a core module, lets keep it around
        return FALSE;
    }
 
    public function upgrade($old_version)
    {
        // Your Upgrade Logic
        return TRUE;
    }
 
    public function help()
    {
        /**
         * Either return a string containing help info
         * return "Some help info";
         *
         * Or add a language/help_lang.php file and
         * return TRUE;
         *
         * help_lang.php contents
         * $lang['help_body'] = "Some help info";
        */
        return TRUE;
    }
}
 
/* End of file details.php */