OK. It's possible to remove/replace the MV1's batteries without ripping apart the housing!
The trick is to remove just the bottom cover. It has some adhesive holding it, but it's a rubbery
adhesive with a very light grip. Use a small, thin bladed screwdriver on either side of the
latch mechanism and pry the bottom cover off.
Save yourself a lot of grief and take out the latch and it's spring. Set them aside someplace
safe. If you don't do this, the latch will fall out anyways and the spring could fly off to parts
unknown.
Next, pry out the batteries. I put duct tape on my screwdriver and was able to pry the
batteries up about 1/8 of an inch. I then used pliers (covered with more duct tape) to extract
the batteries. You might need to remove some angled tabs with a utility knife, not all of the
housings have these tabs (see photo #2 below).
Put in your new batteries (observe the polarity!), assemble the latch with it's spring and then
snap on the bottom cover. The inside of the cover opposite the latch has a groove that fits
a tab on the bottom cover, so there is no need to glue anything back together.
Image #1. All the parts. Too much disassembly!
Image #2. The tabs that hold in the batteries. Not on all holders.
Image #3. Another holder, without tabs. Just the right amount of disassembly!