Notice the picture showing fingers pointing to the cables. The bay chamber wall stores four mushroom head screws for the second hard drive. If you replace an old drive out of PowerMac G5, remember to retrieve those mushroom head screws back and install them to the sides of the new drive.
If your PowerMac G5 has two hard drives installed and you would like to replace the one in the upper bay (A bay), you have to remove the drive in the lower bay (B bay) first in order to have the space to allow the upper drive to "fall into."
There are three levels of "racks". The drive in the upper bay occupies the upper two levels. You will not notice this when you pull out the drive. It is only when you are going to insert a new drive into the upper bay (A bay) that you wonder how it goes. First, you insert the drive into the middle rack and push the drive toward the back of the bay. The middle rack will guide the drive and raise the inner half of the drive to the top rack level. Then, you insert the two side feet (the mushroom head screws) of the outer half of the drive into the top rack. Once it clicks into the position, it's done.
I am happy to announce that my iBook gets its 2nd life with the newly implanted hard drive. The screw marked with the yellow circle was worn out. I ordered a set of "Screw Extracting Pliers" (small) from iFixit in the hope of remedying the problem. Initially, the pliers do not have enough space to work on it because the screw sits in a narrow plastic basin. I file some of the surrounding plastic away to make room. Finally, the pliers "bites" the screw out. Yes!
The screw is put back when the iBook is assembled.
To put back the AirPort card with the clasp (wire brace), make sure the card is pushed against by the wire, not clamped over. The latter situation indicates that the card is not seated deeply enough.
My journey of replacing the hard drive stops at step 29. The screw marked with the yellow circle ("One 6 mm Phillips with a small head in the lower left corner") is very tight. The torque I applied wore out the screw head and it becomes the death sentence announcement of the iBook. Sad.
Each rubber foot has three large tabs occupying 3, 7, and 11 o'clock positions, while a small tab at 9 o'clock position. When you place those rubber feet back to the ring housings, make sure their small tabs aligning with the opening gaps around the rings.
Yes, the rings have to be put back and flushed with the lower case surface. Otherwise, the rubber feet will not stand evenly.
The "keyboard locking screw" is a transparent plastic screw located between F5 and F6 function keys.
"Continue to run the spudger around the front, right corner." This is nearly impossible for me. Instead, I use a small flathead screw driver to gently open up the tab at the corner.