I just got too curious so I took out my battery and L bracket and discovered that it would be easy peasy to remove my hard drive with a simple hooked piece of wire. Maybe it would work better using two hooked wires. I could very easily hook the bottom side of the two end-most screw holes that are used to secure the thin metal lid on the drive.
Next I dug out an old 30MB iBook drive from my stash and discovered that it too would be easy to hook and pull. I have included a scanned picture of it and the hook that I use for this type of take-apart stuff.
http://members.all2easy.net/gregory/HDhook.jpg
On my MacBooks Hitachi drive I would be able to hook one of the holes that is shown in the jpg. Maybe not possible on the drive in the jpg. The Macbook drive has those holes kind of recessed so to speak.
On this jpg though it would be even easier yet to hook the corners of the casing as it is recessed. Might be kin of hard to see.
However, your drive may be all different. The reason I mentioned bicycle spokes is that they are common, very stiff and small enough I should think. The hook in my jpg is smaller than a spoke, just for reference. You undoubtedly have some piece of wire on something that could be cut bent and used.