So I did a little online research, found two excellent sites [1|2] that describe the iPod HD replacement process, and decided to make the repairs myself.
What follows is my own experience.
Back cover of my iPod. Note: When a computer product is sold by two competing companies, and something goes wrong with it, .
My handy-dandy Leatherman pliers, screwdriver and knife
Removing the back cover. Using a flat head screwdriver, gently loosen the steel back plate from the white front piece. Then separate the drive from the connecting IDE pins. Note that the connector will only easily connect with the hard drive in one way.
Separate the hard drive from the iPod unit.
Hard drive removed. I'm told that one should be careful with the kapton flex flat cables (the flat translucent brown things indicated by the arrows), which are actually flexible circuit boards. The metal traces inside them, particularly where they flex or change width are prone to breakage and it's difficult to tell that they're broken.
"Top side" of the hard drive.
It has a hard white plastic collar that removes easily. Hold onto it for later.
"Bottom side" of the hard drive. Note the blue foam padding and blue rubber bumpers.
The blue rubber bumpers are easily removed. Note that they have a "bumpier" side and a "smoother" side. The "bumpier" side will face you when you look at the "bottom side" as you reattach them later.
The soft blue foam padding is easily removed with a pocket knife or straight-edge boxcutter.
The 4th Generation iPod 40GB hard drive with all padding removed. Note that the product number "MK4004GAH" indicates drive capacity ("40") and year of manufacture ("04"), and that this number may have changed when you want to buy a new drive.
Old and new drives. The new drive's model number is now "MK4006GAH". I got it from the nice people at eWiz. I've also read that you can put in a 60GB drive (MK6006GAH) in place of the 40GB drive, but I didn't want to chance that yet.
To reassemble, just reverse the above instructions. I used a glue stick to reattach the blue foam padding to the "bottom side" of the hard drive.
According to fred_d,
"Once youve upgraded the drive, you will need to simply run disk mode (3rd and 4th gen hold down |<< and >>| as soon as you see the Apple logo), connect to the pc (you should see it come up as an external drive in my computer) and then run the iPod updater which is a free download off the Apple website. This will format the disk and load the software.
"After this just reboot the iPod (hold menu and play for 3rd gen, select and menu 4th gen) and plug in. n.b. if it says do not disconnect, DONT disconnect it. When its clearly not in use by the computer any more (not updating etc) right click on the safely remove hardware icon and click on it.
"Turn the iPod back on, plug it into iTunes and you should be good to go!"
fred_d was right! It worked just fine for me. Was able to have 400+ CDs worth of music reloaded onto the drive within an hour.
Total cost: about $140 (with tax & S&H) for the hard drive, plus about 45 minutes total deconstruct/reconstruct time.
