Follow the instructions here:
https://www.mobileread.com/forums/sho...istration+hack
But make sure you download and substitute the latest versions of the hacks from here:
https://www.mobileread.com/forums/showthread.php?t=88004
**NOTE** installing the USBNetwork hack is not for the faint of heart. Search the Kindle Developer forum if/when you run into trouble. There's quite a bit there about the 'registration hack.'