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 B
operation B consists of 5 mission.
the missions aren't hard
If you are struggling with a mission i have have added a walhthrough of all mission in operation B with gold stars for this achievement
*Warning the video might contain
spoilersB-1 starts 0:35
B-2 starts 3:22
B-3 starts 8:20
B-4 starts 12:33
B-5 starts 15:28
*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.