By forcing Windows Vista to use some default drivers, you can access the unit's memory like a USB memory stick. You just need a software tool to read out the XTAF-file system of the unit.
Step 1: Open the Unit
Step 2: Solder USB connector to PCB
Then connect the black, green and white wire to the pins according to the picture:
The two left leads are shield and ground, the 3rd lead from the left is the +3.3V power pin which will be fed by our voltage regulator from step 3. The next two pins are D- (white) and D+ (green) from USB. The 2nd from the right is GND again (black from USB). The last pin is shield again (as you can see).
Note: Think forward and carefully adjust the cable length to your USB port to fit the case length and inner height! The parts have nearly no space to the top (I needed to modify the case).