When I had my roof fitted last year the side bits were flapping about so I took it back to the guy who fit it and he tightened the tension cables at the C pillar side. I think he took the roof down about half way and then unstuck the roof from the roof frame to get into the cables, he then tightened them up and stuck it back down. Did the trick anyway. As for difficulty ? He knew what he was doing and it was easy, I wouldn't have known what to do.