The quest must be done in a few stages, the easiest way is to /claim the shard then examine it. It will show an image of a large toothy gateway. Those are portals which are located in the northern part of Thundering Steppes. You will now have a quest to find out what's going on with the gnolls.
Short version: Freeport > Commonlands > Nek Forest > Thundering Steppes.
Long version: From Freeport go to Commonlands northwest corner, that's the gate to Nek Forest. Once inside Nek Forest, hug the left wall and run to the docks. The mobs are 18+'ish so be careful.
From the docks (repair while you're here) in Nek take the TS bell. Now you're on the docks of TS. Run off the docks and hug the right wall and follow the road to northern TS. By Tower 2 you'll find one of those gateways being guarded by gnolls.
As soon as you get close enough for agro, they will scoop you up and send you to an instanced zone, captured, requiring you to escape. It's no easy thing to do, so be fully repaired and equipped. I believe you can do this when in a group.
The main entrance to Splitpaw is in the far southwest corner of TS near the Skindancer Gnolls pool. When you go in, you'll be in an instanced zone of the Upper Tunnels where you must make your way down to the lowest level and into the main Splitpaw Zone.
Once you get to the main Splitpaw Zone, go around and talk to the various gnolls to pick up quests. You must complete 3 quests to "Gain The Trust Of The Gnolls" and receive a teleporter shard that casts Return to Splitpaw (teleports you to Splitpaw where you can stay there or exit to Thundering Steppes). If you fail to complete 3 quests or log off for the day, you will return to find yourself outside the main entrance in Thundering Steppes, having to do the access sequence all over again.
I did that blasted access quest and got to Splitpaw at least 6 times before completing the 3 quests and getting the shard.
Good luck!