Download the KitKat update.app and place it in the dload folder (I'd advice you to place the dload folder on your internal SD).
Optional: Factory reset (this fixed reboot issue for me)
Then do a local update.
After that, download the kitkat twrp on your pc and extract the .img
Plug in your phone, and enable usb debugging
Get ADB, then shift + rightclick the folder and select open command prompt here.
adb reboot bootloader
fastboot flash recovery recovery_twrp.img
After that, reboot your phone in recoverymode and flash gapps. At reboot, it will ask you if you want to root. Do that.
Hope I helped.
Sent from my P6-U00 using xda app-developers app
Edit: have it, missed drivers-hisuite helps