Although this quest is listed in the Quest Journal as repeatable, it isn't as the scroll cannot be examined once the quest has been completed.
Steps[]
Kill a Sandscrawler diplomat, spawned by approaching ( 516, -120, -715 ) Copy/waypoint 516, -120, -715.
Kill a Kromtorr diplomat, spawned by approaching ( 1041, -118, -368 ) Copy/waypoint 1041, -118, -368.
Frame the Sandscrawlers by examining the body of the Kromtorr diplomat that you killed in step 2. Regardless of the actual place where you killed the Kromtorr diplomat, his body will spawn at ( 1059, -117, -356 ) Copy/waypoint 1059, -117, -356.
Kill the Sandscrawler goblins around the barricade at ( 535, -108, -830 ) Copy/waypoint 535, -108, -830.
Frame the Kromtorr Giants by examining the dead body of the Sandscrawlers that you just killed.
Report to Captain Sterling at ( 94, -88, -777 ) Copy/waypoint 94, -88, -777.