[drummachine]

I could only install Duokan by Hand.
Try it with ssh via USBnetworking or install the KUAL Extension kterm.
Copy DK_System Folder to the root Folder of your Kindle.
Open kterm (or ssh):

cd /mnt/us/DK_system/install
chmod +x top.sh
./top.sh

I had to do this procedure twice (there was an error on my first try)

EDIT:
oops, the Folder Name is "DK_System" not DK_system", so the right command is:

cd /mnt/us/DK_System/install
chmod +x top.sh
./top.sh