Start by removing the six Phillips PH2 screws holding the top of the drive on. They may be a bit hard to loosen, as they're really old. Don't strip 'em! I couldn't get a good picture of all six screws to fit in the cropping area, but they are at the drive's four corners and also at the middle of each of the long sides of the rectangular body.

Peel off the stickers on the drive cover as well. This voids the warranty (who cares at this point?), but is necessary to expose the rest of the screws holding the cover on. Remove these screws also (there should be 2 torx TR7 screws and a 9/32" nut (circled in red in the third picture) - remove the nut as well - you may need a socket).