1. Download the file http://svn.mozilla.org/projects/sumo/trunk/language_files/%LOCALE%/language.php (replace %LOCALE% with your locale string) and open it in a text editor of your choice
2. Search for the line including "### start of untranslated words" (that you've seen on the site). Be sure to remove the // at the end of each line you're translating.
3. Save and e-mail the file back to me (djst at mozilla dot com) and I'll upload it on the server so we can try it out.
If all goes well, we should be able to use this for all untranslated strings.
今来週中に language.php の一部だけ修正、翻訳して David に送付し、問題なさそうなら順次残りの部分についても作業を進めていくつもりです。
SUMO の UI L10N に協力してくれる人は立候補よろしくお願いします。(^^;