The easiest way to destroy the Scarab is by using the "Stop and Drop" method, which is basically when a player takes the heavy weapons and gets on the passenger seat of the Hornet. While holding any weapon, have the driver take off and hover above the first Scarab (your choice). Hover about five to ten feet above the Scarab, then have them take cover up on top near the blue plasma cannon. Have the driver stay in the vehicle and kill the Brutes around the entrance, then have the driver go around to the back while the driver flies behind the Scarab. The passenger on the Scarab should shoot the power core until it is set to explode. That player then jumps off the back behind the Scarab. Have the Hornet pilot drop down while the other player gest in the passenger seat again. Fly to the next Scarab and out of the blast radius. Repeat the process with the other Scarab.