Re-orient your iMac so it sits upright on the stand.
Insert a plastic card up into the corner of the air vent slot near the top of the rear case.
Push the card toward the top of the iMac to release the front bezel latch.
Pull the front bezel away from the rear case.
Repeat this process for the other side of the front bezel.
It may be necessary to apply several layers of duct tape to the top of the access card to aid in releasing the latches.
If the bezel refuses to release, try pressing the lower edge back onto the rear case and repeat this opening process.
Alternatively, you can use a strong magnet by holding it to the front top left/right corner of the display. You will hear a snapping sound when the hatch is released.
Peel back the two EMI tape strips from the left and right edges of the display.
During reassembly, it is helpful to use several small strips of tape to hold the EMI shielding along the left and right edges of the display footprint out of the way before lowering the display into the rear case of your iMac.
Use the flat end of a spudger to pry the optical drive connector up off the logic board.
It is helpful to insert the spudger under the top or bottom edge of the optical drive connector and twist to separate the connector from the logic board.
Apple's "engineers" didn't learn much about deflection and material stiffness when they went to "college", so this optical drive is particularly difficult to remove because the bracket flexes too much. The next few steps require some patience and a good amount of force.
Insert the flat end of a spudger into the gap between the optical drive and its bracket until it contacts the chassis.
Grab the spudger as close to the surface of the optical drive as you can, then depress the release tab with your thumb while pulling toward yourself.
The wedge shape of the spudger may cause it to slip out of the gap toward yourself. Be sure to press the spudger in toward the rear case while squeezing the release tab.
Use the flat end of a spudger to press the bottom edge of the lower optical drive bracket release tab toward the lower edge of the iMac.
The optical drive should now be free from the rear case.
Maneuver the optical drive out of the rear case, minding the two plastic pins molded into the rear case near the open end of the optical drive that can break off.
Maneuver the optical drive out of the rear case, minding the two plastic pins molded into the rear case near the open end of the optical drive that can break off.