Upgrading Guestbook from ver 2.2 into 2.3

I have my Guestbook version 2.2 is running, and I would like to upgrade it into version 2.3. Is anyone can help me? Do I have to upgrade the whole things or I just need to upgrade some certain files?

Best regards,

Tony

Replace all files and update your datebase with the sql file

CREATE TABLE book_pics (
msg_id int(11) NOT NULL default '0',
book_id int(11) NOT NULL default '0',
p_filename varchar(100) NOT NULL default '',
p_size int(11) unsigned NOT NULL default '0',
width int(11) unsigned NOT NULL default '0',
height int(11) unsigned NOT NULL default '0',
KEY msg_id (msg_id),
KEY book_id (book_id)
) TYPE=MyISAM;

ALTER TABLE `book_config` ADD `thumbnail` SMALLINT(1) NOT NULL, ADD `thumb_min_fsize` INT(10) NOT NULL;

Thank you for your support. The program is working just great with the newest version. I like this program very much.