Clean the fish.  Then make two cuts down each side of the spine from the top all the way to the tail.  Do not cut all the way through the fish, just the skin.

Cut the spine in half under the gill, put your filet knife under the spine, go all the way to the tail and cut the spine out of the fish.

Starting at the top of the fish, put the filet knife just under the rib bones and make sure that you can see your knife through the skin.  Cut back toward the tail, making sure you do not go too deep into the trout.

After you have made these cuts, you can then use any of the other recipes on this site to cook your trout!  Good luck and enjoy.