Xardas points you to Ur-Shak, a shaman the orcs cast out, who can get you safely through the Orc Enclave. He is holed up in a castle ruin to the east, and reaching him means a long walk through the mountain paths with 
Bloodhounds and Razors in the way.
This is mostly a trek with a few fights strung along it, so pack for the road.
- Healing potions.
- A decent weapon.
- The best armor you can wear.
What you meet on the way depends on how much of the area you have already cleared, but expect Bloodhounds under the bridge and a group of Razors near the end.
Fast travel to Xardas' Castle and head out through the downstairs entrance. Turn left and go up the path. It should look familiar, since it runs through the spot where you fought the 
Stone Golem earlier.
Follow the path up, clearing anything you have not already dealt with, until you reach a large, well-lit open area. Keep going forward and up. At the next section, turn right, then left, and follow the path higher until you step out into the sunlight.
Outside, stay close to the cliff face on your right and follow the hill up. Soon you reach a point where you can drop down to save time. Use the rocks and ledges to break your fall in stages so it does not cost you much health. The left side is the safer way down.
From the bottom, carry on past the ruined castle, bear left, and keep straight. A bridge comes into view ahead.
Head underneath the bridge. One or more Bloodhounds may be waiting here, so deal with them, then follow the path to the left.
Black-green flags start appearing along the route. They are your sign that you are going the right way, so move from flag to flag, keeping the cliff on your left.
A couple of Razors block the path as you press on. Put them down and keep going through the archway. More Razors wait at the top, so be ready for a larger fight.
Save before the top approach. The Razor group near the entrance can catch you out if you walk in low on potions.
Once the entryway is clear, head up and around into the area ahead. Ur-Shak is here. Talk to him to finish the quest.