This mission begins at Michael's house and can be started by either Michael or Trevor. After the cutscene, either go to Sandy Shores Airfield if you're using Trevor, or to the airport if you're using Michael. Michael will automatically go to North Yankton, while you will need to fly there yourself with Trevor.
There will be another short scene and if you're using Michael, you will need to drive to the cemetery. When you get there, go inside and to your grave for another scene. After it's over, you'll be in a firefight with the Chinese with Michael. You only have a pistol because of the airport security, so make sure you pick up the weapons from the fallen enemies.
Don't forget to use the larger tombs and headstones for cover, as well as use Michael's ability to slow down time and get good shots off. If you can get headshots, get them but don't leave yourself exposed too long. You want to head towards the entrance, where the last set of guys will be blocked by a train. Watch the scene when you get to your car and you'll be control of Trevor. Fly back to the airfield and land the plane to finish the mission.