Start from Yahnur Market. Simply follow the quest marker to the points on the map. After talking with Diji, slowly begin working your way to the rift. The mobs are close together and it's easy to over-aggro. Kill the margonites around the rift to close it. DON'T FORGET! Talk to Diji after killing the Margonites, before mapping out of the area, or you'll just have to do it all again.