You will download install-tools.deb to the FLASH.. not the internal memory/MMC because it will need to USE the internal memory to write the data to.. it has to reformat the internal memory and remount it meaning if you try and install from it you will end up with a failure.

The best thing is to install the install-tools.deb to you default Documents directory while in Flash.. make sure the external card is NOT IN the n810.. then install the install-tools.. during the process you may see some Memory card warnings and stuff while the partitions are done.. and then it copies/clones your flash to your internal memory.

Then you can reboot and boot into the internal MMC... and put in your external Card.

And yes.. look in my sig.. I have Diablo in Flash, cloned to internal 2GB MMC, and the full Debian Deblet installed on my external MMC.