Here is a download link for 4.4.2 FRANCE GENERIC version, downloaded from XperiFirm and bundled in Flashtool. Flash this ftf in flashtool :) Enjoy your 4.4.2.
Don't kill my google drive with downloading, I will post MEGA link in 2 hours :)
Here is the download link for stock Nexus 4.2 Launcher. Resolution is right, so it looks far better then Google Now Launcher on our Xperia M2 devices. Simply unzip it and install as normal APK. Works perfectly.
DOWNLOAD Stock Nexus 4.2 Launcher
But if my bootloader is different than this Kk may hardback my device?
Flashtool is always a safe haven...if your phone somehow gets bricked, you use flashtool to restore it back. Works the same for UNLOCKED / LOCKED bootloader. This is not OTA...
do i need to flash whole partitions or only system & kernel ?
I never flashed this any other way than full firmware. Simlock.ta gets ignored anyway, and thats it. Wouldn't exclude any other thing from installation...just do a full setup....
Download Mobitel Slovenia branded 4.4.2 firmware for Xperia M2 D2303 here. It usually comes with little bloatware, just few Mobitel applications, I think they can even be removed without root. Flash this FTF file in Flashtool (flashtool.net).