Place the cooked salmon on a piece of greaseproof paper before you begin.
Using a sharp knife, cut the skin just above the tail, then cut through the skin along the back and in front of the gills. Using the knife to help you, work from head to tail to peel off and discard the skin.
Place a serving plate under one side of the greaseproof paper and flip the fish over onto the plate, using the paper to help you. Remove the rest of the skin. Remove the head if preferred.
Scrape away any dark flesh with a knife. Split down the centre of the top fillet, then carefully remove and lay the two quarter fillets each side of the salmon.