Hey all,
So I desperately needed help figuring out how to gain root access on my Paperwhite to replace some screensavers. I asked a lot of people, but they seemed to direct me back to the readme files which were -- in honesty -- confusing. So, I decided just to go ahead and try it my own way. Luckily, it all worked out. For those confused by the whole process, hopefully this helps you. I was using a Mac, and a Paperwhite on 5.3.1 firmware.
Spoiler:
1. First, you'll need to jailbreak your Paperwhite. You can grab the jailbreak, and the instructions for it,
right here. Follow it through.
2. Next we have to install USBnetwork.
Get it here. Plug your Kindle into your Mac, and drag and drop "update_usbnet_0.6.N_install.bin" to the root directory. Now on your Kindle go to [Menu] -> Settings -> [Menu] -> Update Your Kindle. Once done, eject and unplug your Paperwhite.
3. Now we need to test if it's installed correctly. On your Paperwhite, tap the search icon at the top. Type in ";un" without the quotations. It'll go back to the home screen thereafter. Now plug your Kindle into your Mac. If it doesn't show up as a device like it normally does, it's worked!
4. What it is now is a network device of sorts. Head to System Preferences, and you should see it listed as a RNDIS/Ethernet Gadget. Now, on this click on advanced > Configure IPv4 > Manually. In "IPv4 Address", use: 192.168.15.1. Leave everything else as it is. Click ok, and then apply.
5. Now we should make sure your Mac can "see" your Kindle. I advise at this point to turn off the Kindle's WiFi. Go to Terminal, and type ping 192.168.15.244. If you start seeing numbers with ms after them, it's all good. Nearly there. Close Terminal.
6. Now it's finally time to gain root access. For this, you'll need an FTP client. Transmit is a good one, and it has a free trial.
Grab it here. Once opened, click SFTP at the top. Now the following: Server = 192.168.15.244 Username = root Password = *leave blank* Initial Path = /
7. Click connect, and you should be in!