I have an STX-RC 8 sp rear derailleur that I'm rigging up to my latest project bike. The problem is that the upper pivot (where the b-tension screw is) has rotated past its usual range (past the little nub -which serves as a stop - on the pivot body). This typically happens when a twig/branch gets caught in it. This makes it impossible to mount to the derailleur hanger, since the b-tension screw is about 90 degrees - in a clockwise direction - from where it needs to be on the derailleur hanger's notch. I have taken the pivot apart by removing the cir-clip from the pivot bolt. The spring looks fine. I've reassembled the pivot, and can find no human way to get it back to the way it's supposed to be.
a) with the circlip re-attached, the pivot won't rotate back over the pivot body's nub/stop.
b) with the circlip not attached, I can rotate it over the nub/stop, but it takes an indordinate amount of tension (rotational, as well as pressing down), and with both my hands tied up (one rotating, the other pushind down to ensure the groove of the pivot bolt is exposed enough to get the circlip back in) leaves me no way to get the circlip back in. I've tried rotating in both clockwise and counterclockwise directions. No luck.

I've tried everything I can think of, including trying to thread it in to the derailleur hanger (from outside AND inside the chainstay) to get more leverage. No luck. I've checked my Zinn bike manual, which simply says to put the spring back in the holes made for them and re-assemble, like its a walk in the park.

There MUST be a way to do this. Has anyone had any experience with this? I wasted over an hour of time trying to get this done tonite. Help before I beat the thing senseless