Well, I replaced the CR2032 memory backup battery this weekend. No big deal, just have to remove a bunch of screws from the perimeter (don't forget to remove some under the front edge of the desk) and then the control surface hinges up from the back. I used a 20" long paint stick to hold the unit up and open while I was working inside. Once open, you can see the battery pretty much dead center in the bottom of the mixer on a PC board. So that I didn't loose all the preset settings, I plugged the mixer back in and turned the power ON. With the power ON, I then removed the battery and replaced with a fresh one. Maybe a little dicey doing this with the AC power supplied and the mixer turned on - but this method worked. No settings, preset or scenes lost after cycling power....