After previous step has been completed, the giant robots will continuously wander the map until the following step is completed.
This steps is best done with two players, and at least one player will require the "airstrike" beacon or G-strike, one player should enter the robot and press the red button.
Immediately after the button has been pressed, the second player should throw the airstrike beacon into the field next to Generator 5. You should see a down plane which will make it easier to identify.
If the G-Strike is thrown inaccurately, it will disappear and you will hear demonic laughter. If done correctly and soon enough from pressing the red button, the robots will fire an artillery on the seal, breaking it.