First, you'll need to open your XY Finder. On the side edge of your XY Finder, you'll see an indent that can be opened with a nickel(or screwdriver or a key). Insert the nickel, and twist to the right and left sides. Once the XY Finder has popped open, you'll be able to access the internal battery.
Remove the battery and pop in the new one you'd like to use, make sure the + side is face up, you'll hear a beep if it's been installed correctly. Finally, line up the two sides, and push around the edges until you hear your XY Finder snap shut. All done!
Replacing the battery in an XY2 follows a similar process as above, but it is more difficult to open the XY2 Finder. We recommend using a flat head screwdriver instead of a nickel, though the nickel can work. Please be mindful of the wires connecting the 2 halves of the Finder. If the wires are damaged the Finder will no longer be able to beep.
If you don't have a new CR2032 battery, you can buy them here on Amazon.
The video has also been attached below.