Step 22
Remove the 5 Phillips screws from the bottom shield.
Peel back the yellow tape and foil shielding outlined in the image.
Step 23
Lift the bottom shield off.
Step 24 — Upper Case
Remove the following 4 screws on the bottom of the computer:
Two 3 mm Phillips from the left side of the computer.
One 4.5 mm Phillips near the latch mechanism (this screw may be missing in 800 MHz iBooks)
One 14.5 mm Phillips near the front, right corner.