1. Eliminate enemy personnel (x15) with pulwar sword
At the start of the mission, ignore the horse and look around the starting area. You will find a body that you can interact with to pick up the sword. Simply use it to melee kill 15 enemies over the course of the mission to complete the challenge.
2. Destroy enemy helo with a mortar
In the cave where you meet up with your contact close to the start of the mission, you can find these in an access door. Once you grab the mortars head out of the base soon after heading through the gate, you should see a helicopter taking off, hit it twice with a thrown mortar to blow it up for the completion of the challenge.
3. Destroy tank with anti-tank mine
You will be able to pick these up from an unlockable chest in the first zone we need to go and defend. It is up the top of the ruined structure where you pick up the stingers. When you return to the main area, there will be tanks about, jump off your horse and plant a mine in front of a tank to blow it up for the challenge.
4. Run down enemy personnel (x10) on horseback
Simply ride into 10 infantry units with your horse.
5. Destroy enemy helo with truck mounted MG
Close to the entrance to the base is an MG truck with a turret on the back. Around halfway through the mission, a large number of enemy helicopters will converge on the base and attack. Hop onto the truck’s turret and take out one of them for the challenge to be complete.
6. Destroy enemy helos (x4) at North Pass
After destroying the arch, return to the main area in front of the base and turn left. After a short distance you will see four enemy helicopters. Destroy all of these with the stinger to complete the challenge. Note you can also get the challenge listed below for taking out a helicopter with the stinger without using lock on easily here as the helicopters will remain relatively stationary as they are dropping off troops.
7. Utilize stinger (without aircraft lock-on) to destroy enemy helo
After destroying the arch, return to the main area in front of the base and turn left. After a short distance you will see four enemy helicopters. Destroy one of these with the stinger without using lock here as the helicopters will remain relatively stationary as they are dropping off troops.
8. Eliminate enemy personnel (x25) using alternate fire mode on stinger
Simply shoot enemy troops without the lock on function of the stinger. Kill 25 of these to complete the challenge.
9. Collect intel (x3)
Complete the mission without dying.