I have done many you can twist and turn it upside down and just about any hdd can get in.
the 1tb samsung has proved to be most difficult hdd.
The hardest ssd was a kingston 64gb.
thin and undersized ssd's are easy.
this goes for all 2011 mac minis except the server.
due to the 2 hdds in place you need to slide the logic board just a bit to pull the top drive out.
there is a trick to avoid that once you take the silver screen out screw in a longer pair of screws to the hdd and you will get some leverage to get it out.
I had bought a kit from iFixit designed for adding a 2nd HD.So I bet if I was trying to install a Samsung 830 vs. a 470 I would have had no problem aligning the screws?