http://codex.wordpress.org/Upgrading_WordPress

tar -cvvf wordpress_backup_[date].tar public_html mv public_html wordpress_old_[version]

用 phpmyadmin or mysqldump 等等

http://wordpress.org/download/

tar -zxvf [filename].tar

mv wordpress [自定]

wp-config.php

// ** MySQL settings ** //
define('DB_NAME', 'wordpress');    // The name of the database
define('DB_USER', 'username');     // Your MySQL username
define('DB_PASSWORD', 'password'); // ...and password
define('DB_HOST', 'localhost');    // 99% chance you won't need to change this value

// You can have multiple installations in one database if you give each a unique prefix
$table_prefix  = 'wp__';   // Only numbers, letters, and underscores please!

http://[DN or IP]/[path to wordpress]/wp-admin/upgrade.php