1) Download the full package from http://www.phpbb.com/downloads.php, unpack it to a temporary folder, say, /tmp/phpBB2
2) Copy the new package to a temporary folder
$ cp -R /tmp/phpBB2 ppp
3) Copy the old config.php file
$ cp forum/config.php ppp
4) Install the new package: point the browser to http://mydomain.com/ppp/install/update_to_latest.php
5) Remove the install/ and contrib folder
$ rm -rf ppp/install/ ppp/contrib/
6) Copy chinese language package
$ cp -R forum/language/lang_chinese_simplified/ ppp/language
7) Modify logo location, and replace it with the correct logo
$ vi forum/templates/subSilver/overall_header.tpl ppp/templates/subSilver/overall_header.tpl
and search key word logo to find the correct line
8) Copy the Avitar folder
$ cp -R forum/images/avatars/gallery/Avatar_pack_1/ ppp/images/avatars/gallery/
9) Test the new forum at http://mydomain.com/ppp. Remove the old folder if everything looks fine
$ mv forum /tmp/forum.mydomain; mv ppp forum
10) To fight spam registration, I also changed the keyword “agreed” in all files to some other word.