Default Samsyng Galaxy Trend Duos GT-S7562C - changing CSC

Hi, XDA-Developers,
I am back from China where it bought this little phone (which is DUOS - means supports two SIM Cards):
The phone is China Unicom Branded and updates in KIES just fine:
AP: S7562CZNUANB1
CP:S7562CZNUANB1
CSC:S7562CCHUANB1

It does not seem to be SIM locked, since local SIM cards seem to work fine:
As i am located in bulgaria and have two major problems:
1. Lack of any Google apps and services - no google maps, google play store..
2. Lack of any Bulgarian local settings (only English and Chinese).

It seems the ROM is multi-CSC - displayed when starting in recovery mode.
However all operations related to changing CSC or installing google apps seem to require rooting the phone, which i am not able to find any reliable information. Any information i find is about GT-S7562 which is pretty much different phone it seems.

So i am a bit stuck on what i can do.
There is mentioning that you can flash CSC from another region using ODIN, however i could not really find reliable information about this and source of proper CSC files.

Best Regards, Chavdar