Gilling and Gutting Trout In-Fisherman - October 18, 2011 Insert the knife point through the throat or tongue connection.Cut the throat or tongue connection.Insert the knife point in the anal pore and begin cutting forward.Run the knife up the stomach lining to the gills.Holding the throat connection, pull it toward the rear of the fish to remove the gills and intestines.Slit the kidney at the top of the body cavity down the middle for the length of the fish, and scrape it free with your thumb (or use a spoon).The cleaned cavity is ready to be stuffed, or the fish can be cooked in any favorite recipe. Get Your Fish On. Plan your next fishing and boating adventure here.