The (Advanced Solo) can be done with either a Mercenary or as a duo with another player. You must be level 92 to enter the zone and have the Chains of Eternity expansion. The Ashlok sometimes whip you towards and behind them, so take care what you're facing to prevent falling down.
Level 95^ spider. Burn down fast. He will drop white sacks that hatch into several spiders. These sacks have a lot of hitpoints, so better focus on killing the boss.
Dirge strat: Aracanocht itself is fairly easy but it prevents you from changing targets at some point, so you have to kill the adds. With a Dirge, use Veil of Notes (Heroic AA, 20 seconds of 100% Dodge) when the tiny bonedevourers spawn, then focus on green abilities (area effect). They don't have a lot of life. Once they die Aracanocht should become the main target again, and Veil of Notes will run out. At this point you should be able to kill it before new adds spawn. Use Howl of Death and Thuri's to heal yourself throughout.