From Pirbright Green head south a few yards and turn right into Mill Lane.  After about 0.6 mile park where you can in the large space with several roads and trails going from it (just after Pirbright Lodge).

For the On On head back along Mill Lane and turn right at the end.  After 250 yards take the B3032 Guildford Road for just over a mile to the pub.

Alternatively to get to the start from Guildford, head to Worplesdon and, from Fox Corner, do the above in reverse.