very difficult in my opinion. Bud's Benz sells the new cable for this. They are not expensive. You should buy a new one , in case the old one is worn. The cable connects to the heater air directional box, which needs to be removed if you want to replace the cable. Has a special very unique clip that makes the outer black vinyl part of the cable stay put, while the inside wire moves, opening and shutting the vent to either blow air to the windshield or to the floorboard area. The upper part of the cable has a very unique and special clip also, that is connected to the lever mechanism for the same reason. The wire is threaded through a hole in the bolt. Over this bolt goes the washer and the nut. After the cable is secured with the special clip properly, it's time to put the nut and washer on the bolt. I took the speaker cover off to get in there to do this. The windshield was removed also. I think I used a very small 8mm offset ratchet wrench to tighten the nut , after I spent an hour trying to get the nut on the bolt. A flexible magnet helps with all the mis-attempts, to pick up the loose nut and washer that falls off when trying to get it placed on the bolt----- My heater air box was actually warped and was bending and kinking my cable. I bought another air box from dr Benz. and put on a new cable. It works like a new one now. It took years to find out why the clear lever would not work correctly.--whewww-This all brings back bad memories- Dr Benz saved the day for me on this one. And yes, Dr Benz somehow found me one of those special retainer clips I was missing. Members should remember this guy. He always seem to find stuff in his old boxes of parts. His value to me over the years have been immeasurable during the restoration of my 250sl
