1. Work under cold running water or over several sheets of newspaper. Grip the fish by its tail and scrape it from the tail towards the head, working against the direction in which the scales lie, using a fish-scaler or the blade of a blunt, thick-bladed knife. 

2. Cut away the dorsal, pelvic and anal fins using a strong pair of kitchen scissors. 

3. Slit open the belly of the fish from the anal fin up to the head and pull out the guts. 

4. Cut away any remaining pieces of gut left behind in the cavity with a small knife and then wash it out with plenty of cold water. 

5. To barbecue or grill the fish, slash the flesh 4 or 5 times down each side. Rub it with oil and season with a little salt and pepper.