Above is a cross section showing the approximate location and orientation of the radial bones on a salmon/steelhead. I have shown the two cuts I make (cut 1 and cut 2, in that order). The radial bones end in the area just above the ventral fins, and can be easily located with your finger. The reason for the first cut on the top is so the knife can easily follow the curvature of the bones, then the second cut is simply a matter of following parallel to the first cut, but on the other side of the bones. This will leave about 1/16 to 1/8 sliver of meat with bones removed. I do not cut the skin if I want to cook whole fillets.

Part of the dilemma of offering advice on an open forum, is that everyone has his or her own ideas of what is best. So let me say that I offer this as a way I use occasionally. Like when I’m broiling or bbq’ing fillets for company or kids who are not very familiar with eating fish.
It works well when making deep fried fish and chips using salmon or steelhead as well (skin removed for this one). I guess it’s important to add that when I cook fish, except as fish and chips, it is with the skin on. Removing the radial bones makes for a nice eating event for guests. A little classier than grabbing the needle nose pliers out of the toolbox and working over the fish before it’s served.

One last personal preference: When I broil fillets with the skin on, I put the meat side down against the foil first and broil the skin until it is dry, then I turn it over on a fresh piece of foil and add my special spices and finish broiling. I have found that this method insures that the fish is not slimy on the skin side, and makes it very easy to serve and eat.

Again....just my preferences....hope it helps