Duokan OS is clumsy. So let's strip it down to launch the PDF reader from Kindle launchpad. We will need to extract the Duokan atchive and then copy select files to the Kindle DX.

Prerequisites:
1. jailbreak
2. launchpad

1. Create the following folders in the root folder of Kindle:
   
   Code:

   DK_Documents 
   DK_Pictures
   DK_System

2. Extract the Duokan archive
3. Copy the following folders into the Kindle
   
   Code:

   DK_System/lib
   DK_System/system 
   DK_System/Savers 
   DK_System/bin/DKPrivateProfile 
   DK_System/bin/doc2html 
   DK_System/bin/ebook

4. From the DK_System/DK_Update folder select the subfolder corresponding to your device (dx, dxg, k2, k3). Copy its contents to the DK_System on Kindle, except for the bin subfolder!

To delete this stripped down version of Duokan from your Kindle, just delete all folders DK_*.