The operation is simple since the cage is fastened with just a single screw. Install the drive into it and put the cage back in place.

It’s the same thing with the hard drives:

Take the cage out (it is held by one screw, too), fasten the drive and put it back again.

The exhaust fan on the side panel didn’t feel at all comfortable after that, though:

It is in part blocked by the optical drive. You may want to use a “shortened?drive to avoid this problem ?there are many such models available now. Otherwise you’ll have another source of noise, which is not welcome in a HTPC. Next I had to connect the interface cables and that was the second time I regretted my having not read the manual ?the +5V standby voltage cable from the display is to be attached to the reverse side of the display controller card which is hidden under the optical drive. So I had to remove the drive again to do that.

So, you should definitely read the manual before trying to assemble a computer in this system case.