I am using the G9860 variant that has BRI/TGY/CHC roms, the N9860 should be same. All those 3 roms are interchangeable.
I used odin and flashed the full CHC rom, the 4 files. There is 2 CSC files, use the one that wipes all data not he home CSC to prevent any issues.
You can go back to BRI/TGY without any problem.