The only way to update the Spica is to use the PC Suite that came with your phone. install it and just wait =]. the suite is pretty useless for anything else but update.
Once your on the PC Suite, you will see a button saying
Firmware update.. when the update is out we can use that. Or talk to someone in a 3 store but the only other way is to send it off and i dont think you would want that XD