Attached should be two images. The first is the entrance of HFR. You can see the overpass is already up above you and ahead a little bit. The second image shows approximately where to AOE, bomb, or trap so that the damage will reach the patrol. This will not pull the entire instance but will pull 60-80% depending on whether the first boss comes or not.

Name: enter_HFR.jpg Views: 2772 Size: 66.5 KB
ENTRANCE. LOOK UP.

Name: aoe_spot.jpg Views: 2683 Size: 74.2 KB
APPROXIMATE AOE PULL SPOT.