I got this right after I got the Master of Deception achievement
- Load up
Mission 4 - The Storm- Play through until you reach the Stormtroopers walking up the road
- Wait for them to pass
- Follow the Stormtroopers that passed
- Take them out
- In the right corner you can pick up a barrage
- Continue the mission until you reach the next set of Stormtroopers
- Use 1 grenade on the 2 troopers facing the wall
- Use 1 on the trooper on the stairs
- Go up the stairs and use 1 on the 2 troopers opposite you
Here's a video I made on this
This achievement starts at 1:14