I would like you to click right on the main photo, under the eMachines logo.
This produces several views.
To the upper right 8 small views are shown.
Go to the second row, and one at a time, click on the Middle photo, and the photo to the Right.
This shows you that, facing the Front of the computer, the Right Side Panel removes.
Clicking on the photo to the Left, on the second row, shows the Back of the computer.
Little hard to see since it is Black.
There is a Philips head screw to remove, from the right Side Panel, and towards the Top.
It is to the left of the Top, of the grille hole vent area.
There is a Philips head screw to remove, from the right Side Panel, and towards the Bottom.
It is to the left of where you plug the power cable in.
There is a finger pull formed out of the back of the Side Panel.
Pull back towards the back of the computer.
May only slide so far, then is tilted out at the top, and brought out to the side, and removed.
Look at the Middle photo on the 2nd row again. There are TABS molded from the Front Cover.
Black in color just like the Front Cover.
One at the Top, one in the Middle, and one at the Bottom.
These tabs are Gently brought out, to the Outside of the computer.
They are just Eased out a little bit, so the hooked end on them clears the metal framework of the computer case.
(Don't get carried away or they may break)
The Front Panel is gently swung out a little to the Left, where it then removes.
From here allow me to present a video from HP, and replacing an optical drive. (CD/DVD drive),http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00981303&tmp_task=useCategory&cc=us&dlc=en&lang=en&lc=en&product=3436817
There are many different styles of mounting the optical drive.
The above is one style.
Some just use Philips head screws.
Some have a green plastic piece, that the screws on the side/s of the optical drive, slide in a slot in the green piece of plastic.
There is a plastic 'arm lock' that is gently eased to the outside, and just enough so the screws will clear it, when sliding the optical drive down the slot, and out of the Front of the computer.
All I see are SATA connectors on the motherboard, and no IDE (PATA) connectors.
Therefore your replacement optical drive will be a SATA model.
This is an example of a SATA -> data cable, and it's respective connector on the motherboard,
Color does NOT matter
SATA connectors on the motherboard MAY be of different colors, or all the same color. (Black)
Different colors designate the SATA connector order.
SATA 0, SATA 1, SATA 2, SATA 3;
Or, SATA 1, SATA 2, SATA3, SATA 4.
The different order designations may also be silkscreened on the motherboard, close to the individual SATA connectors.
The Harddrive is usually plugged into SATA 0, or SATA 1.
Optical drives go to any of the rest of the SATA connectors.
(Or multiple harddrives in a R.A.I.D. configuration)
The beauty of SATA though, is that you can plug that optical drive into ANY SATA connector on the motherboard, and BIOS will find it.
Also note the L-shape in the SATA data cable's connector, and the matching L-shape on the SATA data cable connector, on the motherboard.
Cable only plugs in, in one direction.
A SATA data cable connector, and a SATA power cable connector, may have a Lock on the connector. Near where it plugs in, on the cable connector, and is squeezed down with the thumb.
Squeeze to install, squeeze to remove.
The SATA data cable connector, and SATA power cable connector, are usually a 90-degree bent Elbow, for plugging into the Harddrive, or Optical drive.
A straight-end connector is plugged into the motherboard.
Between a SATA power cable connector, and a SATA data cable connector, the SATA data cable connector is the smaller of the two.
A SATA data cable connector has 7-pins.
A SATA power cable connector has 15-pins,http://www.playtool.com/pages/psuconnectors/connectors.html#sata
REMEMBER, power unplugged to computer, Anti-Static Precautions FOLLOWED.
If you do not know about Anti-Static Precautions, post back in a Comment.
For additional questions please post in a Comment.