1) Download the firmware from the link in the post..
2) Download Odin3 from http://forum.xda-developers.com/atta...1&d=1341114315
and run it with administrative priviledges..
3) Extract the firmware that you downloaded from the link in the post..
4) Turn off the phone, press and hold Volume down+Home+Power button until you get the Download mode. (Press the Volume Up to continue) and then connect it to your computer via USB. (wait until Odin detects you device).
5) In Odin put the extracted firmware under PDA and click on Start..
6) Wait until it finishes and restarts itself.
Note: If your phone is not rooted, you do not need to wipe data and cache. Else after the flashing is complete and the phone restarts, it will go in a boot screen loop. Down worry. Here is how to take care of that:
a) Turn the phone off and then press and hold Volume Up+Home+Power.
b) The phone will go into the stock recovery. Wipe data/Factory reset and Wipe cache.
c) Restart the phone and the phone will go into setup with Russian language as default.
d) From the first screen itself, tap the drop down option and select English from that list and hit next. The rest will be easy to complete (as in adding Google Accounts, etc.)
P.S.: Since this is signed firmware, the binary counter will not increase. To root the JB Firmware, follow this thread after installation of the JB Firmware http://forum.xda-developers.com/show....php?t=2087424