Hmm... I can't
I didn't take notes and it's not like I completely refactored the tool.. as far as I remember I took reconstructor 2.5... it crashed for a few reasons so I looked at the code and did a little bit of debugging, removed some stuff and changed other things in a few places. After a little bit of tweaking it was extracting the Debian live CD and reconstructing it into an ISO successfully. I didn't have to change much and it went quite fast, I didn't even keep the tweaked version after the release.
Most liveCDs are built in the same way anyway. Reconstructor simply assumes you're looking at an Ubuntu disk, so you change a few assumptions in the code that's all. Basically it's always the same.. an ISO containing an initrd, isolinux and a squashed filesystem... you extract all that, unsquash it, chroot into it, make your changes and after that do the exact opposite to rebuild the ISO. It's pretty basic in theory and most of the time in practice as well.