SER Russia CSC:
N915FYOXA1COI1 - U.K.
You will not lose your warranty or do any harm to your device if you flash this. Please note that it's only for N915F/FY. Knox stays 0x0.
Extract (unzip) the firmware file
Download Odin 3.10.6
Extract Odin zip-file
Reboot phone in Download Mode (press and hold Home + Power + Volume Down buttons)
Connect phone and wait until you get a blue sign in Odin
Add the firmware file to AP / PDA
Make sure re-partition is NOT ticked
Click the start button, sit back and wait a few minutes