If there is no hatch to remove the hard drive, you'll have little other choice other than opening the entire case to remove the hard drive.
If you choose to go this route, keep the screws well organized and keep a written list of where each screw and piece came from came from as well as any other pieces that have to come out, as I've had to remove as many as 25 screws to get a hard drive out of a laptop before (Toshiba Libretto U100).