Hello jeaniebear;
I think your Sony Vaio RS210 uses the older style IDE CD and DVD drives - not the newer SATA models.
It looks like your case has those color-matched-to-case fold down DVD covers that hide the actual drive.
After you take off the left and right side panels of your case I think you should be able to remove the entire front face plate.
Behind that you'll see the actual bare DVD drive. From there it's as jsc says. Remove a couple screws, detach a few wires and slip the old drive out, and the new drive in.