Exit the M5 motorway at either Junction 25 (if you are travelling from the North) or Junction 27 (if you are travelling from the South).
The easiest route is via Junction 27 since this avoids the town centres and is a straight run along the A361 to Tiverton and then turning right onto the A396 as far as the Dulverton turn-off. At this point, follow the signs to Brompton Regis.
If you decide to take the alternative route through Taunton, follow the signs for the A358 to Minehead. At Bishops Lydeard, 4 miles outside Taunton, turn left onto the B3224 (watch out for the steam trains on the West Somerset Railway line). This road will take you to the eastern boundary of Exmoor National Park and onto the village of Wheddon Cross. En route, you will see several road signs pointing the way to Brompton Regis.