Yeah, you'll have to boot up the Knoppix version you want to remaster, and copy extract_compressed_fs and create_compressed_fs from /usr/bin and copy those two files to your remaster-box. Or you could try and download those files offline.

Once you have extract_compressed_fs, copy all the files from the mounted Knoppix cd in your remaster box and run ./extract_compressed_fs ./$BIG_KNOPPIX_FILE > $big_knoppix_iso_uncompressed.iso

Then mount $big_knoppix_iso_uncompressed.iso with -o loop and copy the files to a directory.

Then your done.

Good luck,

-a