Nearside sliding door won't respond to opening lever on outside. Took inside door cover off (2 screws, the rest poppers) oiled up the mech, and got the inside door opener working by lubricating , but linkage seems to have gone between the outside lever and the mechanism. How - just how - just it all come apart? The operating block seems to be rivited in . On the outside there's a plastic surround to the actual lever - this looks as if it prises off, but don't want to try without some advice cos it looks easy to damage. Comments welcome.