Speak to Ayndrew Celladar at 48.66, 1.52, 41.96 inside the building on the docks of Enchanted Lands.
You can stand outside the doorway and hail Ayndrew from outside if you're having trouble fitting inside the tiny doorway.
Enter the Runnyeye Hoard Pits. Take the Halfling Pony near the dock at 38, -1, 20 for a closer ride to the entrance. We found the entrance at 179, 33, -888 .
There are a few goblin totems in this dungeon. They can be destroyed but are not necessary to completing the quest. You have a chance of getting a bit of gold from them (or be attacked by a rat). They are located at 177, -16, -192 , 88, -16, -125 and 133, -16 -134.
From the entrance, head south, then west.
Grab the big boom keg and move it like a house item back at 123, -17, -140 . Move away and wait for it to explode.