the camp site looks difficult and long to access but you need to go round from Saddleworth 'Civic' by car as if you are heading for the road over the pennines, i think this is Greenfield. This is usually signposted for the camp site and gets you onto the large flat camp site which has a sports changing room etc.
Once camped on the camp site the walk to Saddleworth is surprisingly short even at night! Ray