Remaster From Hd Install HowTo
From Knoppix Documentation Wiki
Tip: Language support
Internationalization takes up over 5% of the Knoppix filesystem; removing uneeded language support will free up considerable filespace. Install the package 'localepurge' to remove all the language support you don't need.
apt-get remove kde-i18n*
will clear over 100 Meg by removing all alternate kde language support files except english. Of course if you need support for another language you will only be able to remove the ones you don't need.
