keyboard key cover came off, how do I reinstall?

For the keys, use a small flat head screw driver to gently lift up the key from the backside until you can get a fingernail under it and lift till it pops off. Carefully examine how the scissor plastic key retainer is positioned . Look at the bottom of the key to see how it snaps into it. Lift the sides of the retainer on both right and left side to observe how it works. Take the retainer out and put it back in to understand it. The major problem is getting those little bitty plastic pins into the holes. I use a plastic toothpick to lift and separate inserted from the right. I

Here is a nice website with a lot of explanation and nice pics:

http://homepage.mac.com/simx/technonova/...