While I'm repairing stuff: Cleaning out the opitcal unit

I'll be tearing into my G4 12" Macintosh aluminum today to oil the fan. (another thread on that)

My optical unit has been flakey for the most part. In an assembled state I would try cleaning discs, and ones like that. Many times discs were inserted that the Mac didn't recognize and forget were there. I had to eject those at start up.

Once disasembled, what are some ways to clean the optical drive once the computer is taken apart? Are there ways to remove the drives' outer casing and clean that way?

(As you can see the computer is well travelled and used often. Taking it apart this weekend I finally might have a chance to give this computer some needed upkeep.)

(This computer was handed to me, non-working, as a pile of parts a year ago, and thanks to some how to guides on the internet and some advice here, I reassembled it and bought some replacement parts)

Thanks in advance!