Would anyone know if it's possible to upgrade the firmware via only the external SD card?
My Touch's data connection is broken, the microUSB connector unwelded itself and probably caused some damage to the data controller as it cannot connect to anything; At least it's still charging and can still be used by sideloading books on the external SD

But I'm stuck with firmware 1.9.12 and w/o wifi connection as the Touch is not activated; I have a model B, with a memory chip and not internal SD card, therefore I cannot mess with the file system via a computer.
I guess my only option to activate and enable a wifi connection is to upgrade the firmware via the external SD...