Operation Flashpoint: Dragon Rising

Be careful not to be spotted and do not engage groups of enemies. You need to quietly kill the guy at the top of the first hill then do NOT fire until you pass the house by the road and go up to the pillbox bunker on the top of the next hill. There is a single soldier inside and he'll spot you if your not quiet. Kill him, then continue along the check points. At the top of the next area (after passing what looks like a mine) you'll get to call in a JDAM. Target the station while Han is still inside to unlock this achievement.

On mission Decapitation you must kill HAN and the radio station with 1 airstrike simply go silent for the whole mission only killing the first person right at the start and flank round all the way to the left until you reach the building at the top of the mountain and then when HAN enters the radio station simply air strike that location. =

What the other solutions fail to mention is that you actually have to use your binoculars on Han to initiate his movement and bring up the next waypoint.

Once you’ve reached the first checkpoint, wait until Han lands and watch him with your binoculars. As you watch him, he’ll enter a jeep and start driving away. A new checkpoint will then be placed on a ridgeline to your left, proceed over to it and repeat with the binoculars. Keep tracking him until the next waypoint appears. Proceed down the hill and past the two enemies on your left to the next waypoint.

The next waypoint Han will actually approach, so just stay back a little and wait for him to leave. Either silently kill or sneak past the enemy sniper inside the bunker and continue following the waypoints to reach the last checkpoint. Kill the two enemy snipers and await your orders to call in an airstrike. Do so when Han is inside the radio station and the achievement is yours.

This video shows a decent path towards the achievement:
What I found though was at around the 14:30 mark when Han is going up to the bunker, I just stayed in the woods until he left. I found when I approached the bunker he wouldn't leave half the time. Even staying in the woods its a crapshoot as to if Han leaves or not, and if he doesn't, you have to load last checkpoint, as if you trigger any kind of engagement you'll void your chances at the achievement.

I also found that the video missed that there's a sniper in the bunker. Video author just runs by him & lucks out that A) the achievement wasn't voided and B) none of the teammates died (one time I ran by the sniper with my team they started firing at him and then as I ran past later in the level another sniper killed one of my teammates and then I was detected, voiding my chance at the achievement). Instead I ordered my team to stay put at the bottom of the bunker, then went up & silently killed the sniper. After that I pretty much just had my team follow me & followed the waypoints to the top.

Achievement pops after the JDAM airstrike lands (around 21:15) in the video.