Converting Digimesh Firmware To ZigBee Firmware?

I have been using the Digimesh 900 modules and am please with the ease of use and straight forward networking model.

Question: I have some ZigBee hardware that I need to communicate with and would like to “convert” the Digimesh 900 modules firmware to the ZigBee 900 firmware, how do I do it?

I know this is possible from the notes.

The Xbee 900 modules currently do not have any ZigBee 900 firmware. They only have the digimesh 900 firmware and “Point to multipoint” firmware.