Countering Schleswig-Holstein at Westerplatte

How could Schleswig-Holstein have been countered at Westerplatte in 1939?

Use artillery capable of plunging fire, though the weapons actually available at Westerplatte would decide whether that was feasible.

Any credible answer depends on which Polish weapons were available at Westerplatte in 1939. Schleswig-Holstein was an old pre-dreadnought, so plunging artillery fire is identified as the basic way to threaten her rather than a simple close-range attack. German forces nevertheless failed to take the defended position despite support from the battleship. The ship's bombardment power did not remove the wider difficulty of reducing a determined shore defence.