The battery was incredibly hard to remove. I slid the spudger underneath the battery from the right side as far as it would go. Then, I worked it from the bottom to the top. The battery still was adhered and wouldn't budge using the pull tab. I wound up leaving the spudger underneath the battery at the top and then pressing down on the bottom of the battery to get leverage. After a few strong pushes, and then swapping the top and bottom in the last sentence, the old battery came loose.
I used tweezers to hold the tiny screws and align them with the screwdriver head before taking the screw to the destination hole.
One more tip.. if you don't have any other cartons or containers convenient, use the box that the product comes in as a workspace for holding the tiny screws while you work.