Go to
KUAL thread and read
Important notice *anything* that might be running FW >= 5.9.x: from first post:
Spoiler:
As of right now, and for reasons outside of our control, Kindlets will fail to run on these devices & firmwares, so you can disregard the earlier bit about the azw2 file.
Instead, on these devices, we will have to use the Booklet version of KUAL.
First, the prerequisites: your device of course still needs to be jailbroken, and needs to be running a recent "hotfix" version (the vast majority of you should be covered, only the early adopters might need to update their hotfix). Then, you will have to install MR Package Installer (MRPI). Never mind that it's technically a KUAL extension and that we're in effect doing things in reverse .
Once that's done, put the Update_KUALBooklet_v*_install.bin file (found in the same archive as mentioned earlier) in the mrpackages folder, which you'll find at the root of your Kindle over USB, then eject & unplug you Kindle.
Finally, enter ;log mrpi in the Homescreen's searchbar (in a similar fashion as what you had to do during the Jailbreak), and wait for MRPI to do its thing.
When the UI finishes restarting, you should end up with a KUAL entry in your Library (showing as a personal document).