Cross the bridge near Tearfall Run and go up the ramp to the East Tower. Then, cross the wood bridge (not the rope one) and go through the short tunnel to get to the South Tower. BEWARE! The Iron Pine Butcher wanders the area between the tunnel and the South Tower!
At each tower you will see a circle of flaming-blue glyphs. Step inside and use the Shade Ward. Several mobs will appear but seconds later they will all fall dead.