After a few times, you will be able to stand up and walk around.
You will start to see yourself flicker on top of the bridge. Roll up towards the hill while looking at the water. To get on top of the main bridge at the start of the map, lay down directly under the edge of the bridge. Get on top of the main bridge in Pagoda.Use your rifleman when it turns orange, and your support or demo when it turns red. Use your sniper when the threat indicator indicates that there are men from afar (yellow).
Have a rifleman, sniper, and a demo or support.