Regarding the right side, I found that the 4 clips slide to the left more easily that pull out. However, the front right has a bar which drops into a slots preventing pulling to the left! So ... gently lift the front right (furthest from the screen), pressing just at the front end of the optical slot to bend the faceplate at that point, then gently rock the face plate back and forwards while pulling left, so the that the four clips slide out of their retainers - presto! Remember to bend the faceplate to reassemble.
Quote from dougyfresh:
Regarding the right side, there is a series of 3-4 plastic snap in locks on that side along the optical drive, holding the case down in lieu of screws. It takes serious pressure to remove the snapped in pieces (just lift straight up). You should also make sure to line them up when you put the casing back on. Another picture might help show that portion better