To Hijack a UFO you must have unlocked your Rocket Jet Pack. To Hijack a UFO you will need to get close to a UFO by Pressing
. Once you get close you will see a Orange Circle telling you to press
. Then you will climb on top of the UFO and you will need to Press
very fast. Eventually the UFO Gunner will find you and start shooting you. You will then need to press
to move around the UFO and the Gunner will follow you. Simply go back to where you were and keep Pressing
until the Cover is off. Then you will need to press
left to right to disarm the Gunner and finally take over the UFO.