Bricking the device is possible (rare but possible) but it's the only chance you have to remove that code. You can easily find language ROM on the internet by searching.
Now here's the flashing guide for Samsung SGH-i780
1. Samsung USB Driver:
2. Russian ROMS:
3. E1 English PDA ROM:
4. Mirage Updater:
Tried and tested best result by flashing it using Windows XP OS.