DISISO="$HOME/Downloads/grml64-small_2017.05.iso"
squashfs="/live/grml64-full/grml64-full.squashfs"
mkdir ~/livecdtmp
cd ~/livecdtmp
mkdir extract-cd mnt
sudo mount -o loop "$DISISO" mnt
sudo rsync --exclude=$squashfs -a mnt/ extract-cd
sudo unsquashfs mnt$squashfs
sudo mv squashfs-root edit
sudo cp /etc/resolv.conf edit/etc/
sudo mount --bind /dev/ edit/dev
sudo mount -t devpts devpts edit/dev/pts
sudo mount -t proc proc edit/proc
sudo mount -t sysfs sysfs edit/sys
sudo mount -o bind /run ~/livecdtmp/edit/run

cd ~/livecdtmp/edit
sudo chroot ~/livecdtmp/edit zsh

#####Run These Commands in Chroot#####

export HOME=/root && export LC_ALL=C

###When Complete run these Commands###

apt-get clean
apt-get autoremove
rm -rf /tmp/* ~/.bash_history
exit

###After Eixting Chroot###

sudo umount ~/livecdtmp/edit/proc/sys/fs/binfmt_misc
sudo umount ~/livecdtmp/edit/proc
sudo umount ~/livecdtmp/edit/sys
sudo umount ~/livecdtmp/edit/dev/pts
sudo umount ~/livecdtmp/edit/dev
sudo umount ~/livecdtmp/mnt
sudo umount ~/livecdtmp/edit/run

echo "Creating ISO"
sleep 3

cd ~/livecdtmp
sudo mksquashfs edit extract-cd$squashfs

sudo genisoimage -l -r -J -V "REMASTER" -b boot/isolinux/isolinux.bin -no-emul-boot -boot-load-size 4 -boot-info-table -c boot/isolinux/boot.cat -o ~/REMASTER.iso ~/livecdtmp/extract-cd

cd ~
sudo chmod 777 ~/REMASTER.iso