Here is someone's post (with coords) from another page:

Tricky to find
Score 6.2    by Tig60, 1.3 years ago
These dudes can be a pain in the [butt] to find and it is wise to bring a friend.

Just [roam from] camp to camp just outside the building, and you will come across an elite dude,

this dude is a machine type thing.. kill him and you get your quest item

i killed mine at 22,75

if you don't have cords, that is the most south west camp. he was walking along the path.