Batteries Fisher Price Kick N Play Piano

It's not easy.  Unscrew the screws to the point that you're sure that they're just spinning.  Then, gently pry the cover off (see how next to the screws, there's an indentation that looks like it could be used for this purpose? I'm not sure if they were truly designed for helping you get under there, but they work!)  I used a flat head screwdriver and just gently pryed (it was still pretty tough, and when I eventually got it off, it made sense.  There is a rubber-y seal that keeps the back on VERY tight!)