To shuck an oyster, hold in a folded dish towel and insert an oyster knife through the hinge of the shell. Keeping the oyster level, wriggle the knife to sever the hinge muscle, then push it in a bit further and twist up to lift the top shell. Tip the juice into a bowl and remove any pieces fo shell from the oyster. Slide the knife along the bottom shell to release the oyster. The juice can be used in various dishes including fish stock.