Originally Posted by Hawker
the only way back is an Odin flash of the original ROM as modems, of course, do not get backed up in a CWM backup.
If you go to advanced backup and restore, custom backup job in Philz recovery you can backup the modem. I haven't tried this feature though so I can't say how reliable it is.
On another note has anyone managed to flash a modem with mobile Odin? They always fail for me.