I have the standard Magic Store Sofa with the cool back that flips over

and down to extend the seat as a bed. Each arm on the side of the sofa back has a metal stop so the back won't turn 360 degrees. However, periodically (like now), one of the two stops slips past the arm. Then I have one stop above the arm and one stop below.
Until now, I've been able to move the back around to slip the stop past the arm. Not now. I could try to unscrew the bolt for the arm, but the nut on the other end is below the surface of the wood, making it difficult to keep the nut from moving when unscrewing the bolt.
Sighhh. Anybody else run into this problem?