Meet the troll that's going to ask for something. Give him the crystal so that Illidan will get a potion. Use this potion so that the troll will disappear and quickly go east to find something to heal as the potion gives a sickness.
Head east through the seals then north and then west. Get the weed then head east and south down the ramp and then west to the next weed. Get back on the ramp and head east then south for the third weed. Then, head back, cross the bridge and a bit south to cross the parallel bridge. Go east, a bit south, get the weed and cross the bridge back. Head west and then south to cross a smaller bridge. Then, go east, cross the bridge to the east and head south and get down that doodad ramp to get the next weed. Turn back and head east but don't go south the ramp but a bit more east. Head south, take the weed and turn back to the ramp to take that weed as well. Quickly, go west, cross the bridge, don't go west on the ramp. Instead go south, on the bridge and then west until reaching the ramp to the water zone. Get there and head east to the ramp, walk up, then quickly west to the last weed.
Now, get east to the tuskarr. He will turn Illidan into a seal and leave through a portal. Once through, quickly get south to the ruins before the tuskarr hunters kill Illidan.