Thank you all so much! I only had to remove three screws on my E-420, the two inside the card compartment, and the one next to the "Made in China" label on the camera bottom next to the battery door. I was then able to pry the joint "behind" the card door open enough to see the metal rod that the door hinges on and slip it out with a small flathead screwdriver. The new one went in as easily. I had expected this to be painful and time-consuming, but it only took about 15 minutes.