Ever drop a TV remote and break the battery cover? Don't worry. It's easy to make a replacement. All you need is some scissors, paper, and a piece of plastic. I used the side of a soap container.
For my fix, I needed a battery cover for my old Casio CTK-450 keyboard. I've had it since I was three and I've probably been missing the battery cover since I was four.
You can use this technique to replace any battery cover that uses the tab and clip design.