Gently bend the Jimmy outwards to pry the crack open a little larger and lift the lower housing up a small amount.
There are several plastic clips on the lower housing that fit into a channel in the aluminum top housing. Your goal is to use the Jimmy to push these clips inward enough to free them from the channel, while gently pulling up on the lower housing.
In the next few steps you will be removing the AirPort and Bluetooth antennas (shown in red) from the internal frame. Be very careful, as breaking the brackets will require replacing the internal frame.
We will first remove the AirPort antenna, located in the lower left corner of this picture.
Remove the following four screws securing the internal frame to the bottom housing:
Three 6.7 mm Phillips #00 screws
One 9.5 mm Phillips #00 screw
The screw in the lower right corner of this image is recessed deep in the internal frame and longer than the other three screws. A flashlight and a thin screwdriver aid in removal.
Lift the internal frame off the bottom housing, starting at the rear edge, until you feel the concealed edge connector on the motherboard disconnect. Then lift straight off, minding the bluetooth and 802.11 antenna cables.
When reassembling, the wifi antenna wire routes to the inside of the vent and then over the top of the vent.
Push the PRAM battery toward the center of the logic board and pull it up out of its holder. You'll have to push the battery in further than you'd expect in order to get it to pop free.
Don't bend the metal finger too much or it will break off, requiring a new logic board.
When inserting the new battery, make sure the side with writing along the edges faces the black plastic holder. You should also insure that the metal connectors make contact with the battery (you can bend them forward if they do not).
