I can't do much to the car, but that job is PISS EASY!!
just undo the adjusting nut off the lever and the two bolts holding the cover on where it goes through the floor. Feed it through and just follow it along - very self explainatory. Doing only one side is even easier because you have the other side for a reference if you forget where something goes. But probably not recommended just replacing one side as they stretch over time so the pressure may be uneven between the two sides. for how little they cost just do both - good practice anyway!!