Once you start, move quickly to the barn in front of you. Once there, do not bother with crawling through the hole in the wall. While outside, follow the guard that is walking around, but do not attack him. Use the first chance you get to go into the barn he is guarding and climb the ladder. Once there, slowly approach the guard and shock him until he dies. Once this is done, turn around and pick up the gun and ammunition. Turn around and talk to the people. After that, pull out the gun and kill the guard patrolling the barn. Next, run out the large doors and turn to the left. Follow that until you get to the point to where you have to kill the four men. Once done, go to the roadblock, then go to the booth. However, go outside the booth and pick up the detonator and other items. Turn around and go down the street. Kill all the men. Go into every building to pick up all the ammunition and guns. When you need to use a health pack, use it. Once at the bridge, place the dynamite and go left to the building that they tell you to go to. Once up on top, place the detonator, but do not push it until the clock-like timer is all most out of time, or just when the front car is on the bridge. After that, slowly kill everyone, one by one. Once again, go into every building you can to get the rocket launcher. Once everyone is dead and you are done, follow the red arrow until you get the item you are looking for.