Hi Mark,
Far far away is my temporary location, my work carries me pretty far afield....my home is in San Diego.
Be sure to let us know how you resolve your issue....and stay in touch as your topic develops. I'm sure that there will be other additions with more specific links / info on getting your iMac opened up for replacing the optical drive.
As I recall from previous posts here and elsewhere (most recently at the
MacFixitForums, now archived) there have been several conversations regarding the details you seek.
