From clockwise M25 (heading towards the QE2 Bridge)
Take the last exit before the QE2 Bridge (Jnc 30). At the roundabout take the first exit on to the A13 towards Tilbury/Southend. Take the Grays exit and follow directions below.
From the A13 Grays exit
After leaving the A13 take the roundabout exit signposted towards Orsett (Stifford Clays Road). After about half a mile turn right (still Stifford Clays Road). Follow the road for about a quarter of a mile and William Edwards School is on the right.
From the A1013 (old A13) from Stanford-le-Hope
At the Daneholes Roundabout (Blackshots) take the Blackshots Lane exit. Follow Blackshots Lane all the way to the bottom (about 1.5 miles). Follow the road round to the left and William Edwards School is on the left.
The ground is shown on the map below, use zoom buttons for more detail: