You can't access the H/D caddy from the back of the PC unfortunately.
You need to remove the side panels or get access to them.
Once you manage that, there are probably 4 screws ( 2 on either side) that you unscrew.
You also need to pull out the ribbon (thick cable that is going into the back of the H/D) and also the power cable.
Once all of those are undone, you should be able to slide the H/D out of it's caddy - probably need to push it backwards.
You might have some problems popping the sides off of the PC.
Gently does it. No mad sledgehammer tactics.
K.D
August 2010