I've got the same question too. I also have a question about the ISO compression. I tried following the Remastering doc on this website (except for all the apt-get update step) and everything worked except that I ended up with an ISO image too big to fit back on the CD! The only thing I added was the nvnet.o module which is quite small.

Is there a different compression method used for the standard Knoppix discs?

Jim