Jailbreak Kindle PaperWhite 2.

An alternative reference is http://forum.51nb.com/thread-1441039-1-1.html

Jailbreak

Original post is: http://www.mobileread.com/forums/showthread.php?t=186645
1. download kindle-jailbreak-1.10.N.zip & extract it.
2. Extract contents of kindle-jailbreak-5.4.zip to PW2's root directory.
3. Eject PW2 & update it by 'setting/setting/Update Kindle'.

Install KUAL(Kindle Unified Application Launcher)
Orignal post is: http://www.mobileread.com/forums/showthread.php?t=203326
and http://www.mobileread.com/forums/showthread.php?t=233932
1. Download KUAL-v2.3.zip & extract KUAL-KDK-2.0.azw2 into PW2's documents directory.
2. Eject your PW2 && run 'Kindle Launcher' in your content.
3. PW2 shouts out about whatever something that it can't run, you need install Mobileeread Kindlet Kit.
4. Download kindle-mkk-20140214.zip.
5. Extract relative Update_mkk_*.bin into PW2's root directory, for PW2, it's k5.
6. Eject and update PW2.
7. Now you can run KUAL.

Install BackDoorLock hack - prevent silent updates.

Otherwise Amazon will push update without your agreement and you will have to re-jailbreak.

Original post is: http://www.mobileread.com/forums/showthread.php?t=205666&highlight=backdoorlock

1. Download backdoorlock_10.zip && extract the update_backdoorlock_10_*_install.bin to PW2's root directory.
Note: k3g is for 3G edition with a serial number leading with B006 & k3gb has B00A.
k3w is for Kindle Keyboard WiFi. Any others uses *_10_install.bin.
2. Safely eject PW2 and update it.

Install Koreader(Better than Kindle reader which always shouts out insufficient memory)
Original pos comes from http://forum.51nb.com/thread-1441039-1-1.html
All downloads can be found at: http://pan.baidu.com/s/1nt17R1R

Good luck!