This trophy is obtained by overriding your first Tallneck.
Tallneck's are shown on your map as a blue "long neck" dinosaur machines. What you need to do is locate one of these machines, then find a high area along it's walking path (R1 when using your focus) that will allow you to jump onto it's body. From there you climb your way up to the top and override the port on it's head. This will also let you see all locations for a portion of the map.
Note: You will need to be able to use "override". I believe you need to complete the main story mission "A Seeker at the Gates" to obtain this ability.