I am sorry to revive almost 3 years old thread, but I would like to add one improvement, which will be useful to people, who are not familiar with command prompt.
In the guide in the part called "
FLASH NEW DIAGS WITH SSH AND KERNEL" is where some steps can be simplified.
After extracting
Fastboot_win_public.zip, you go to the folder "
src" and then run the "
cmd.bat" file. (It will be called just "
cmd", if you have hidden files with well-known extension)
Once you run it, the black command windows appear.
Now just enter:
and press
enter and you are in the directory with
fastboot.exe, no matter, how deep in filesystem you have extracted the archive (e.g. C:\Users\yourname\Documents\kindle\fastboot).