You can do it yourself. Click the Canon Japan link above.  In the Q&A from Canon:

Q : How do I update the firmware?

A : It can be updated by copying the downloaded file to an initialized (formatted) CF card (SD card) by the EOS-1D Mark III, and then loading the card in the camera. Please refer to the PDF file at the end of this page for more details.

Please note the following when updating:

* Do not turn off the main switch of the camera during the firmware updating process. When using household AC power supply, be careful of power failure.
* Also, do not open the memory card slot cover or press any button, dial, or switch. If the camera’s power supply is interrupted during firmware updating, the firmware may not load properly and the camera may require repairs before it can be used again.

Additionally, see this .pdf file:

http://web.canon.jp/imaging/dc/PDF/eos1dmk3_fib-e.pdf

Good luck.

Eric

If I take it to Canon in Toronto Ontario I will be without my camera for at least 2 weeks.

There must be an easier way.

I am stumpped.

Larry