You need Yifan Lu's GUI Launcher!
Based on Pat Hartl ad remover.
On your PC:
1) Copy the Screens and Banners that you want to put on your Kindle in this directory!
2) For each Screen and Banner combination, you need one *.sh file, for that rename the screen1.sh file as you wish and change in that file screen1.png to your screensaver and banner.png to your banner.
3) Change the menu.json to access your *.sh files instead of screen1.sh
4) Copy screensaver folder into the extension Folder
On your Kindle:
5) If you have got advertisements, run noads.sh in Launcher->Screensaver
6) If you already removed the advertisements, just run the Screensaver you want like "screen1.sh" in Launcher->Screensaver
7) Enjoy!