Take the M4 to Junction 4B, come off and join the M25 (signposted Gatwick M23). Keep left to join M25 and travel to Junction 12 to link up with the M3 (signposted
Leave the M3 at junction 7 and bear left onto the A303 (signposted the South West).
Leave the A303 at the A3088 Yeovil junction (the Cartgate Roundabout). At the end of this road (5 miles-ish) turn left at the roundabout. Go up the hill past the crematorium on the left, and supermarket on the right. Go straight across the roundabout, past Halfords/warehouse units and the ground is on your left.
Ground picture courtesy of www.footballgroundz.co.uk.