Let Lien know when you are ready to return to Cobalt Scar.
Speak to Osh, who is back near Yeppa at 4260, -1095, 2050 .
Wait for him to create the altar, then speak to him again to receive a blessing.
Return to the tunnel and destroy the three bone barriers. For each barrier there is a nearby risen shaman apprentice (usually in a room on a side-path) that you have to kill to allow the barrier to be attacked.
as of 5/2/13, Bone barriers do not update correctly for group members! Do this solo to complete it.
Kill Salton (98^^).
If you die, be sure to speak to Osh again to receive another blessing which dramatically increases your stats, making Salton soloable.
When Salton chews up a body, he will emote. Joust out at this point. He will refill his health to 100%, but have a lower overall health.
Wait until after the message about a red burst exploding around Salton before engaging him in combat again. Getting hit by this AoE will do massive damage (~50-121k).