This mission can be completed with a very small squad if you're careful and methodical.
*You will need at least two teammates alive in order to complete the secondary objective.
Objective 1: Secure the Bridge
As soon as your squad spawns, everyone should run to the right, hit the dirt and start shooting. There will be rebels on the far end of the bridge to the left and some that come from the building atop a hill. Having a grenadier or a sniper rifle that can destroy vehicles will help with the machine-gun-mounted truck that attacks from the other end of the bridge (alternatively, someone can just snipe the gunner and it's no longer a threat). If anyone needs an ammo resupply, head up the path on the hill and grab it next to the building.
After you secure the bridge, you'll move toward the construction zone. Be alert for two rebel marksmen (not positive, but I've personally seen 1 up there for sure) that can snipe you from atop the dish in the center of the map. Take them out quickly! You'll most likely have a patrol of rebels behind one of the large dumptrucks and a contingent of them around the corner here to your right. Make sure this area is pacified before proceeding.
Objective 2: Disrupt Communications (Destroy the Comm. Towers Simultaneously - At least 2 players are required).
At this point, if your group is large enough, you may decide to split up and head toward each comm tower. If you're in a smaller group, I recommend having everyone head for the tower on your right (west side of the map, I believe). Stay close together, with one person sending the drone to scout ahead. Stay near the walls on either side of the ravine to maximize available cover and be mindful of rebel flanking maneuvers on your left side. Because our group was so small, we stuck relatively close together and cleared this side of the map of rebels, the area around the first tower, then headed toward the far side (south, I think) of the map, leaving the comm tower standing for now. I'll come back to this objective later on in the solution.
Objective 3: Secure Comms Center
This is the group of buildings at the very back center of the map (south, I think) and if you're coming from the right side like my group did (it was just down to two of us at this point...tense!), take your time to funnel rebels to the bridge (we had a nice crossfire going here) or in the narrow paths leading to and away from it. Next, there will be a few guys near a mounted turret facing the center of the map that you can grenade or sneak up on. Depending on your noise level, more rebels may advance on the Comms Center from the direction of the other comm tower. Sometime soon after killing the three guys near the turret, you should get the Secure Comms Center objective complete. Now, just slowly make your way over to the comm tower on the other side of the map, taking out rebels as you go.
At this point, my teammate and I cleared a path back down to the construction zone he stayed back by the second comm tower while I took the drone with me and ran back through the construction zone to the first tower, where we syncronized placing our demo charges so that we simultaneously destroyed both comm towers (hit Y to place the charge). Really satisfying when completed correctly.
Objective 4: Extract
The extraction zone is atop the north end of the large dish in the center of the map. The two of us met up at the mounted machine gun on its south side (where the Comms Center is), took out a couple of rebels and made our way to the top of the dish. At this point in the mission, I believe more enemies spawn in the construction zone, so be wary of them flanking you from underneath the dish and take care shooting them from atop it as you have little cover. When it seems clear, head to the extraction zone and wait for the helicopter to pick you up.
All in all, I believe this mission took us 35 minutes, give or take a few.
*I've seen on other solutions for these co-op missions that if you die in a mission, but don't leave (i.e. keep spectating until everyone dies or they complete the mission), you will still get the achievement if all objectives are completed by your remaining teammates.