Bricked my router

Last night while upgrading the Firmware in my (otherwise excellent) Billion 7404VGP-M ADSL modem/router/wireless thingy, I managed to brick it. It lost connectivity at 20% through the upgrade (though the entire file had transferred to the modem) so I left it for forty minutes or so, then rebooted it. Nothing. Reset to defaults does nothing. Gah!

My gripe is that the recovery utility they supply for such situations runs only on Windows and requires a serial port. I have neither.

Why can't they just provide a technical description of what it'll do? I suspect it'll do some trick to verify the modem is alive, then upload by xmodem the new firmware. Or something.

Anyway, I'll go around to a mate's place to do this, probably. Fortunately I work for an ISP so I can probably borrow a modem/router until I get this one fixed.