You should have a theorem available to show that and . Another theorem says that is a field if is irreducible over . So just show that are irreducible (using Eisenstein). It follows that both are fields.

Next show that any nonzero homomorphism has . It follows that , which means . But if , then . Use this to show that is rational, a contradiction. So there are no nonzero homomorphism, i.e. no isomorphisms.