5-speed clutch pedal problem

Hi guys, I'm new here but on my second 1992 5-speed V-6 LeBaron convertible as a daily driver. 170,000 miles and I like it so much that I'm determined to keep it going. Something is wrong in the clutch pedal. I've found and looked at a parts diagram and I have tried to crawl underneath the dash to see what's happening, but it is tough. The cable seems to be slipping inside the clutch pedal shaft, so that I can no longer disengage the clutch. It looks and feels like there is some sort of a plastic ratcheting mechanism or series of ridges that clamp together to hold the cable, and this is what's slipping and seems to be disintegrating. What do I need to replace and where can I get it? Another question, is what's the best way to get at it to take it apart? There is no room to work on this or even get at it!

There's a yellow plastic tab that runs up and down a slot in the clutch pedal shaft and that seems to be loose or not holding when the pedal is pushed. Looks like some of it may have broken off due to age, etc. Any guidance is appreciated. Surely others have tackled this problem.
Pete Phillips
Leonard, Texas 75452