VIDEO TUTORIAL ON MY YOUTUBE CHANNEL!
How to upgrade from a JB rom to KK? you need to have root and a recovery installed on JB rom..if you have you can follow this tutorial!
1.enter recovery and install this: http://d-h.st/sKD
2-install this just to be sure: http://d-h.st/Pqs
3-flash a CWM kitkat compatible :http://d-h.st/e7f
4-go to advanced and reboot to recovery
5-flash your KK rom and gapps
6-reboot and enter the rom! all done!
OPTIONAL EXTRAS AND ADDONS:
7-before you flash a new kernel you have to flash this:http://d-h.st/Pqs and then install apolo KK kernel if you want.http://d-h.st/Z4a
8-download apolo JB configurator from playstore to have BLN if you want, it works fine.
9-if you dont like the cm11 default keyboard, flash this xperia Z1 keyboard with swype:http://d-h.st/Bt3
IF YOU WANT TO GO BACK TO JB ENTER RECOVERY AND USE STEP 1 AND 2. ON STEP 3 FLASH philz RECOVERY: http://d-h.st/VGg or Apolo JB: http://d-h.st/nnA and reboot to recovery..you have the JB recovery and can restore your previous rom or a new one.
NOTE: I USE ALWAYS APOLO JB KERNEL TRWP..SO I HAVE ALL MY JB ROMS backup with that recovery..so i use the same recovery to restore it..if you backup your JB rom with PHILZ recovery flash the first one.
thanks to hawkerpaul for his wiping scripts.