There are four screws you need to unscrew. They are Phillips head. I used a 2.5 Phllips driver to remove. Don't remove the battery just yet

On the right side of the battery, there is a clip that holds two wires (black and white) running to the speaker. Carefully lift those out of the clip.

One the left side, you'll see a white socket where the plug from the battery connects. For me, it was easier to unplug once I started pulling out the battery, but just make note of it so you don't pull it too hard or the wrong way.

Note also that just above the white socket there is a black wire that goes over the little flange where the screw goes in. Might need to pull that up slightly as you pull out the battery. I found it easiest to gently slide the battery to the right.