How can I recover an encrypted 'virtual SD card' on an MC40?

We have to migrate 350 MC40s from Gingerbread to Jellybean.  However, the SD card is encrypted, and on an MC40, it is a 'virtual SD card' so it cannot be physically removed.  Since the SD card is encrypted, we cannot copy the new files to an SD card, so we will probably use MSP.  But we need to be able to recover the use of the SD card.  Once we blow away the old OS, we will not be able to access the SD card.  So how can we format it, or is there a tool to factory reset the virtual SD card?


Thank you.