As this was the only one without a guide and I'd just finished it thought I would give a few brief pointers.
This was quite simple and myself a friend and a random did it second try.
You need to clear up straight in front first. Then head left up the hill. From here clear all below you and North. Then I stayed on the hill and sniped as the other two headed up to the communications tower. You need, once as the secondary objective lights up, to get to the communication tower and blow it up quickly. If not you fail the objective and a helicopter spawns.
Next head to the middle and clear the main building also killing the Dude who is a main objective.
Then I think it was clear up and extract.
A note on extraction; it would not let us saying that we had to clear the landing site. After all of us running around the map for ten minutes, we could hear Mexicans shouting near the mounted gun but no people, two of us killed each other then it let us complete, weird?
Anyway that is from memory and I may have missed something, please add if you know anything more. I thought I would post so at least if you are new to the map you have some idea, or at least more than I did first time.