Where and how can you do that : I am stuck !
Anywhere! Walk in the wild with a sniper rifle and shoot one at the time & let your teammates take out the close enemy's. I think I actually had to shoot 15-20 head shoots.
https://forums.ubisoft.com/showthrea...el-9-headshots
You can use your synchshot drones for this task, but not your AI teammates.
You'll find two guys next to a bike repeatedly across the island. They usually don't move much. I have an AI teammate take out one while I headshot the other. Find another bike and 2 guys (or other stationary soldiers - I didn't risk anyone moving) 10x At least that's how I did it.
Sync shot drones count