If Faroth Mal is grey, the encounter will automatically break and you will need to wait until you can reset the instance. If you are soloing, mentor down to an appropriate level.
For more information on soloing the Faroth Mal encounter, see his monster page.
Once inside, go northeast towards the entrance to Flammable Fur terraporter. The pillar spirals around, go to the top at ( -24, 31, 14 ) Copy/waypoint -23.76, 31.45, 13.70.
From the top of the pillar, jump to the neighboring pillar to the south at ( -23, 33, 21 ) Copy/waypoint -23.12, 33.16, 21.14.
Jump down to the pillar to the southwest at ( -9, 27, 27 ) Copy/waypoint -8.93, 26.84, 27.47.
From there, jump to the next pillar to the west at ( 2, 26, 22 ) Copy/waypoint 1.93, 26.26, 21.69 and go up and around to the top.
Jump across to the next pillar to the northwest and you'll see the terraporter entrance at ( 10, 36, -7 ) Copy/waypoint 9.95, 35.85, -6.67.
When you enter the zone, you start Act I: Intervention. Kill High Shaman Grulv and Lieutenant Kurzitch. This starts Act II: The Hand of Faroth Mal.
Faroth Mal will walk to his throne and make a speech before he is attackable.
There are 3 armor inducers hidden behind 3 breakable walls. Killing these armor inducers makes Faroth more vulnerable to damage. Every so often a big red message will go up on your screen "<playername> has been marked for death!" Soon after, a gnoll with a bomb/barrel will run to that person and drop the barrel on them so they can't move. The key is to have the person called out to run up to one of the breakable walls and wait for the explosion to take out the wall, then have 1 or 2 dps kill the armor inducers inside. The more armor reducers are killed, the easier the encounter becomes.
A discussion page exists which may contain more information