Done it loads of times, like others, in the early 90s. It was a bit of a rite of passage back then, not sure if it's still as popular? I went up and down on the same route, basically the path next to the railway line. First few hundred yards on tarmac was pretty steep I seem to recall, after that, the only difficult bit was the 'rock garden' near the top, I couldn't ride it anyway.
It was worth it back then for the looks on the faces of 99% of everyone else who went up on the railway "you rode a bike up here!!!???" etc.
I remember going through a number of inner tubes on the way down. What was happening was that when braking, the tyre was trying to rotate around the wheel and take the inner tube with it. This would cause the valve to tear off. I learned a long time ago to talc your tubes, minimises the effect greatly.