Destructors

When Elise traveled to Earth for supplies, they left a communication device there to keep tabs. Good thing, as Earth is being threatened by highly advanced and odd aliens. Elise and company find out as they are delivering some of the Amigos to their home world. Barto stays with the Amigos and Elise and crew head to Earth to assist if at all possible. How can they defeat beings who can destroy a planet with the push of a button?