The LinkStation Mini case turned out to be pretty easy to take apart. I used a 1 inch flexible putty knife. There's a slot in the top case between the USB port and the Ethernet port. You insert the putty knife 1/4 inch, and then rotate the knife to lever the back of the case out, so that the top of the case can be pulled up. Then you can carefully remove the top case.
There are no screws or tape or anything, it's just the parts you see here. The aluminum side rails have little bumps that hook into the drives where the screws would normally go.
If you detach the drives from the motherboard be sure to remember which one goes where. If you swap them by mistake (like I did) it doesn't appear to cause damage -- all that happens is that the LinkStation doesn't boot. Swapping them back seemed to make everything work again.
I'm sorry that the images are so bad -- I dropped my camera in the water and it hasn't been right since.
Still I hope these are good enough for people to figure out the parts list or whatever.Update:
Here are some better pictures
Here are some slightly better pictures.