I've got a v3.1 WRT54G with the Tomato firmware on it, and it runs beautifully. I'd like to upgrade the distribution to the Tomato Mod with OpenVPN. I should have enough Flash memory (4GB) to hold the new OS (~3GB), but not enough to hold both the current OS (~2GB) and the new OS at the same time--thus I'm unable to use the built-in "upgrade" functionality from the web interface. Do I have to downgrade to the old Linksys firmware first, then upgrade? Or could I put the .BIN file on a network drive that's mounted to router's file system and then run some upgrade command from the router? Any advice would be appreciated.