If you want to know how to scale fish all you need is a spoon or butter knife to get started. This is the easiest part in the fish cleaning process.
They sell a fish scaling tool, but this is not necessary at all. Scaling a fish is needed when the fish is going to be baked or grilled whole.
To scale a fish grab the tail firmly and take your spoon or butter knife whichever you prefer and start dragging it from the tail torwards the head.
Make sure to get the top of the fish and in between all of the fins and the underside of the fish.
Remember that the scales make a mess and will be around for a long time, so do this somewhere that is easy to clean up.