If there is something to add to the solution or you have any qustion please tell me in the comments.
This is a story related achievement.
in order to get it you will need to complete operation E
operation E consists of 5 mission.
the missions shouldn't be hard
If you are struggling with a mission i have have added a walhthrough of all mission in operation E with gold stars for this achievement:
*Warning the video might contain spoilers
E-1 starts 0:28
E-2 starts 4:48
E-3 starts 9:19
E-4 starts 11:53
E-5 starts 17:41
*Note if you are going for the gold stars you might wan't to listen through the whole video.
*Note i'm not the creator of this video, credits go to Nak3d Eli on youtube.