It is HIGHLY RECOMMENDED to do a "wipe for install a new rom" if you are coming from a different ROM, then install the ROM and gapps for Android 4.4.
I personally prefer the aroma installer from this thread: [GAPPS][4.4.2][Aroma]FULL AROMA 4.4 GAPPS & Aroma Sys. GApps UNINSTALLER. However, I am getting a bit annoyed because it removes stock browser and Message app by default since version 1.5 and I don't like Chrome and Hangout.
I modified the installer and you can find it here: http://d-h.st/DaZ
At first you should update your CWM to latest 184.108.40.206 but it is not required. Of course, if you have formatted your internal or external storage to exfat then it is the only choice.
CWM Recovery(Flash via Odin, for E120L): Thanks to Mr0lala
CWM 220.127.116.11 Advanced Edition / PhilZ Touch(Flash via CWM): thanks to titanic_fanatic and Phil.
6.07.9 for E120L
6.07.9 for E120S
Hellkat-20140110 for E120L
Please note, you must flash them together, and respect the order: 1)philz_touch_6.07.9mod-e120l.zip; 2) reboot recovery; 3) go to mount menu, fomat app-lib; 4) wipe cache; 5) wipe dalvik cache; 6) Hellkat-20140109-dalil.zip; 7) Kernel-20140110-e120l.zip.
Please never format app-lib again unless you want to wipe data, otherwise all your user apps will be no longer usable.