sed -i 's#init=/etc/init lang=us#init=/etc/init lang=de#' grml_0.3.iso
That's all you have to do if you don't want to manually set bootoption 'grml lang=de'. :-)
Notice: Please verify md5sum of ISO (not just the ISO itself but also the CD-ROM via booting with 'grml testcd') before modifiying the ISO because the modification breaks the md5sum of course. ;-)
