What is needed to break through the surface of Europa? How big does a satelite we send have to be to be able to chrush through the ice layer and dive into the ocean on Europa? If a mission should head there, is this a better way of examining the ocean than landing on the surface and drilling through?
There is no feasible way for a human-made probe to crush through Europa's ice layer.

"It is predicted that the outer crust of solid ice is approximately 10–30 km (6–19 mi) thick." (Wikipedia)

It's not even known, whether there is a liqud ocean at all under Europa's ice layer.

Instead of drilling one could try to slowly melt trough the ice.