But, in my understanding, remastering means essentially recompressing a modified UNIONFS, possibly together with other modifications.
You'll get all of this while using a remastered CD by my way with "Install KNOPPIX to flash disk"

The other method is "recombine"; but I don't like it and I tested it not very well. Modifing Knoppix in a real HD-installation is more versatile.

Greetings Werner * http://www.wp-schulz.de/knoppix/summary.html
Own Rescue-CD (Knoppix V6.7.1 remaster)