This task is - in theory - very easy. After you talk to Cross, run towards the first helicopter base. You'll find there a machine hovering right above the roof. Although it is not marked as a target, hijack it and kill the pilots. Thanks to that action, you'll save yourself some time later in the mission.
Helicopters will be your next targets. You can try destroying them with a hijacked machine, but it will be difficult because of lots of the anti-air weaponry on the ground. Instead, better jump on buildings, and then try hijacking the helicopters. Use the Flying Kick ability in order to get close to enemy machines.
In this mission you must visit three helicopter bases. Every time you have an opportunity to change your appearance and fool your enemies, do it - thanks to that you'll get some time to regenerate your health.
Reward: 275000 EP, 1 new event available