This mission is rather easy as it's just an endurance test. You need to kill 20 henchmen, all of whom are very weak. Simply fly around the ship until you've killed 10.
Once you have, Guldo will show up. Make sure to focus him down, as he is noticeably stronger than the rest. After you lower his health, he will flee, and you will go back to fighting all the weak henchmen. Kill another 10, and the mission will end.