500GB HDD failed
Installed a Samsung 470 128GB SSD.
I followed the octomac guide, but it's really not that complicated. It's tedious, but not that complicated. I took it slow and probably finished in about 30 minutes.
Pull off the glass with a suction cup or two. Place it someplace clean and dust free.
Remove the memory cover on the bottom.
Unscrew the aluminum case. Keep track of the screws. I left the camera cable attached. I just flipped over the case and left it there, attached.
Unscrew the screen. Keep track of the screws. Detach two cables (one needs to be unscrewed). I didn't bother detaching the LCD cable. I just rotated the screen 90 degrees and let it sit there. I could still get to the HDD.
Remove the drive, connect the new one. It has a clip on one side and rubber stoppers on the other side. See below. Transfer the heat monitor.
When removing the HDD, note that the top of the drive (nearer the camera) is attached to a black clip. Push the clip toward the bottom of the computer and swivel the drive out. It will rotate until it is perpendicular to the computer.
If you are installing a 2.5" drive, you may want to get a 3.5" frame. But if you get a short one (like the Mushkin one I got), it will be too short and you will only be able to get one set of screws in. Since it's an SSD with no moving parts, it's not a big deal. You could probably just leave an SSD floating around in there and it'd be fine.
The SSD makes everything go SO MUCH FASTER!!