If you have the World Edition of the BB with Verizon that has a simm card, just ask Verizon to "Unlock" it for you. It only takes a few minutes. I had Verizon unlock two BB World Editions and had no issues.
Once it is unlocked, remove the Verizon simm card and insert the new one for Aruba. Your phone should automatically search for a cell provider. Pick the one that you purchased the simm card from and you will than have service. Or, just bring your unlocked phone to either cell provider at the airport, and they can assist you.