Above images © Earthlife.net
Before you begin this exercise, it might be good to review the bones of the fish head. Try this "paper dolls" fish skull model project from Dr. Mark Westneat as a great overview.
At the fish market, obtain a large fish head from a bony fish (this method doesn't work so well for cartilaginous fishes), such as a wahoo or similar. Put it in a crock pot, a common inexpensive item you can get at a thrift store, submerge in water and cook on low. As the bones begin to separate from the flesh, and from each other, pull them out with tongs or long tweezers, and lay flat to dry on paper towels for several days. Take pictures and make notes as the bones are coming apart, so it will be easier to remember how to reassemble them. Remove any excess flesh, and blot the bones dry to remove excess oils. When all pieces are dry, assemble with white glue.
Above images © Earthlife.net
References:
https://www.earthlife.net/fish/skeleton.html