See the author's comments
for detailed information about his own creation
Edit: Great. The kver trick works like a charm. Thx.
For everybody else:
* get usbnetwork23-0.10.tar.gz
* delete update_usbnetwork-dx.bin
* in kindle_update_tool.py change kver=4 to kver=5 in line 333 and 358
* "make update_usbnetwork-dx.bin"
The last part should be clear.
The other hacks can be treated in the same way.