Just got a beast mode upgrade. i5 3450. FREEEEEE. Got a scrapped Dell XPS with it in there, which also has a Radeon HD 7570 1GB GDDR5, 8GB of 1600mhz RAM, which will make a great HTPC card. It's complete except hard drive. I tossed the 2400s in the Dell and it'll be my new bedroom HTPC.
I've been digging through more pics... It looks like the cage is screwed to the case in the front and riveted to the optical bay, which is screwed into the case at the top edge. To just remove the cage without the bay, the rivets would have to be drilled.