I did the same thing and decided to try and fix it myself. Here are the steps to follow after you acquire the new door, which is available online through Boca Photo
for about $16 plus shipping.
On the bottom of the camera remove the three small screws and the one bottom screw on the side (left corner) of the camera. With these four screws removed you then gently pry the camera apart at the seam so it opens about 1/8". Then pull the battery door up and you'll see the steel pin the door pivots on. Pull the door and pin up and out and then slide the steel pin into the new door and reverse all the steps.