It happens to be a funny thing that you mention this.
I just shot a 2 blade into the ground from my treestand.
Armed with replacement blades, I had planned on repairing the heads bent blades.
I tried unscrewing the allen bolt on this head and it snapped in two.
The broken side of the bolt was in the ferrule (or head) with no way to remove it.
Before I got crafty, I called Rage.
To my surprise the rep. told me that the ferrule was bent and not all blades are meant to be replaced. In addition to this there was no resolve or customer satisfaction efforts by this rep..
After this waste of time speaking with Rage, I had my own fix in mind.
I got my cordless drill, 5/32 and 7/32 drills, a bench grinder, a hand grinder, 10D Galv. trim nail and the replacement blades. Shortly after, I had drilled out the broken allen bolt, grinded the nail to fit the larger hole,fit the blades, placed the nail in the hole, and ground nail flush with ferrule (or head.)
There is one fully functional Rage now, no thanks to RAGE themselves!
Sorry to be lengthy, but this was my fix.
Your fix could be the trash can.