Something sucksThe following guide details our Penryn-upgrade exploits. The usual caveats apply if you're thinking of attempting something similar: do it at your own risk!
Staring off, we grabbed the following tools: suction lifters; torx screwdrivers of various sizes; compressed-air duster; a small pot to hold the screws that need to be removed; and, last but not least, grandes cojones.
Accessing the CPU on an iMac isn't the simple affair it would be with a regular desktop. Rather, with the all-in-one design where the screen is integrated into the 'chassis', gaining access to the micro-FCPGA processor is a task in itself; there are no screws on the back!
The way in, then, is through the front. The screen protector is held in position by a number of magnets. We couldn't easily lever it out using, say, a flat-headed screwdriver, however, as doing so would risk cracking or chipping the glass in the process. Do as we did and purchase a couple of double-suction lifters - a bargain at £4.59 each - and use the wonders of suction to gently prise the protector away. Note, though, that it doesn't require forearms like Popeye's; the protector comes away with minimal force.
Here we go. Step one is complete. The protector protects no more. We were careful when putting it down; it's a real pain to clean, folks.
Now we see the 24in WUXGA panel in its naked glory. It's affixed to the chassis via a cornucopia of different-sized screws. We removed them in a specific order and replicated their positioning on a nearby bench. There would have been significant head-scratching if we didn't.
See! It took us around 10 minutes to get to this point..