Ok, I tried the battery swap.

First 2 out of 3 went fine. I only soldered the top side though because its awkward to solder in such a tight space and its strong enough to only solder one side in my opinion.

Now for the 3rd one...The pictures explain it all...









Basically the solder wouldn't jump from the contact that was connected to the circuit board so I thought I would heat up the surface of the battery to help it across...I left it on their too long.