I'm using the bolt and nut solution to replace the sliding jaw (rear window) in my '88, 420 SEL. My question: after I attach the jaw to the regulator arm, how do I get the jaw into the window slot? I'm guessing I have to loosen the arm or am I just not getting the window and arm in the correct position? Obviously, I can put the jaw in the slot and then line up the arm with the bolt. Problem is, I then don't have access to the bolt head to secure it so I can tighten the nut.