Now all screws should be removed.

Carefully lift up on the side that the disk drive came out of and push on the two snaps that are near the front of the hard drive bay.

It should pull up easily. If it doesn't check for missed screws.

Now push it gently sideways towards the other side and it should pop off of the eSata, HDMI, and VGA ports.

Now the back should be fully off.