As sorry as it sounds I went somewhere on the net and got the walk through for the evasion...no way I was torturing myself for three hours just to use some cool weapons.....here it is.

Start to A

From the drop point follow the trail and very soon you will find a fork in the road. Take the right fork. Stay to the left side and hug the wall. Soon you will come to a place where there is a light tower, before you get to the light tower, there is a path over the hill on the left side, take this path. It will lead you down the hill on the other side. Stay to the left to avoid a spotter on the right, the Bridge and the light tower are directly in front of you. Once you make it to the bottom of the hill you have reached checkpoint A.


A to B

Go down the right side of the bridge, and keep going right. After that, you'll come upon a fork in the road, one to a light tower and one with out. Take the one without. You'll have a similar decision again, but there will be a light tower in either direction. Pick the path where the light tower is further away. Then you'll see another light tower, keep to the left go as slow as possible and creep past it on the left. Keep going slow until you get to point B.


B to C

Head right and sneak past the light tower instead of going towards the guarded bridge. Stay on the left, the light will shine on the right against the rock wall. You'll have the cover of the rocks on the left. Go prone with speed(moving too slow here will give the light tower guard a chance to discover you). Use your binoculars before you try to sneak and try to figure out his timing. After you sneak past, get into the valley crawl right and follow that until it ends on the right. Then go up some rocks on the left and you're at checkpoint C.

Hope this helps.
Good Luck!