#get latest package and check md5sum

wget http://wordpress.org/wordpress-2.8.5.tar.gz
md5sum wordpress-2.8.5.tar.gz
lynx –dump http://wordpress.org/wordpress-2.8.5.md5

#if md5sum is OK, then continue 

tar -zxf wordpress-2.8.5.tar.gz
cd wordpress
cp wp-includes/post-template.php /replace_your_wordpress_directory_here/wp-includes/post-template.php
cp wp-includes/version.php /replace_your_wordpress_directory_here/wp-includes/version.php
cp wp-includes/theme.php /replace_your_wordpress_directory_here/wp-includes/theme.php
cp wp-includes/comment-template.php /replace_your_wordpress_directory_here/wp-includes/comment-template.php
cp wp-includes/bookmark-template.php /replace_your_wordpress_directory_here/wp-includes/bookmark-template.php
cp wp-includes/media.php /replace_your_wordpress_directory_here/wp-includes/media.php
cp wp-includes/formatting.php /replace_your_wordpress_directory_here/wp-includes/formatting.php
cp wp-includes/author-template.php /replace_your_wordpress_directory_here/wp-includes/author-template.php
cp wp-includes/rewrite.php /replace_your_wordpress_directory_here/wp-includes/rewrite.php
cp wp-includes/general-template.php /replace_your_wordpress_directory_here/wp-includes/general-template.php
cp wp-includes/capabilities.php /replace_your_wordpress_directory_here/wp-includes/capabilities.php
cp wp-includes/classes.php /replace_your_wordpress_directory_here/wp-includes/classes.php
cp wp-includes/category-template.php /replace_your_wordpress_directory_here/wp-includes/category-template.php
cp wp-app.php /replace_your_wordpress_directory_here/wp-app.php
cp xmlrpc.php /replace_your_wordpress_directory_here/xmlrpc.php
cp wp-trackback.php /replace_your_wordpress_directory_here/wp-trackback.php
cp readme.html /replace_your_wordpress_directory_here/readme.html
cp wp-admin/includes/post.php /replace_your_wordpress_directory_here/wp-admin/includes/post.php
cp wp-admin/includes/update-core.php /replace_your_wordpress_directory_here/wp-admin/includes/update-core.php
cp wp-admin/post.php /replace_your_wordpress_directory_here/wp-admin/post.php
cp wp-admin/edit-attachment-rows.php /replace_your_wordpress_directory_here/wp-admin/edit-attachment-rows.php
cp wp-admin/import/wordpress.php /replace_your_wordpress_directory_here/wp-admin/import/wordpress.php
cp wp-admin/install.php /replace_your_wordpress_directory_here/wp-admin/install.php
cp wp-admin/page.php /replace_your_wordpress_directory_here/wp-admin/page.php
rm /replace_your_wordpress_directory_here/wp-admin/import/btt.php
rm /replace_your_wordpress_directory_here/wp-admin/import/jkw.php
cd ..