The hard-drive has four screws around the outside. You can kinda see them in the picture on the previous page. You have to remove these screws first. I used a Phillips #0 screw-driver to remove the screws:
Now comes the hard part. After removing the screws, it's not immediately obvious how to open up the case. I tried to pull the top and bottom apart, but it's hard to get a good grip because the enclosure is so small. I eventually figured it out by taking a Phillips 2.4mm and wedging it between the chrome and the black plastic right above the USB port. Then I pushed into the enclosure and upwards. Trust me, this is not easy. The screwdriver will probably slip a few times. What you're trying to do is to insert the edge of the screw driver into a little hole that's behind the USB logo (it's actually behind the middle of the logo). Make sure that you don't push down too hard because you might damage the hard-drive controller. Once you're able to hook into the hole, you should be able to push the top part of the enclosure up. It took me a few tries before I got it right; you can see it from the numerous scratches that I have on the plastic:
Once you remove the plastic cover, you'll be able to see the 2.5" drive that's inside the case. The rest of the disassembly is pretty easy.
The drive has some sort of sticky "tape" on it. Maybe it's there to hold it down. It comes off pretty easily. I'm hoping it's not that important because I kinda lost three of them. :p