This is one possible approach to the start of the Central Rib routes. If walking from Woodcroft Quarry (ie: the southern end of Wintour's Leap), pass the 'cubic boulder' described in the guide book (which is about 1m in height, width and length) and then take the next path on your right. This will lead to the place shown here in image 1. From there, follow the arrows I've drawn on these images. There's an alternative way to the base of the route, which I'll upload photos of separately.