I attempted to get under SW by climbing up that moutain next to the flight point, but i cannot seem to make the jumps to climb up, so i gave up there.
later on, some guy showed me this method to get under SW. I searched the forums and didn't find anything.
Here we go:
1. Goto this spot in stormwind.
2. Jump onto this box, then jump up towards the lamp thing.
3. This might be a hard jump, but you'll eventually land on a little invisible plaatform. Once on this platform, jump on top of the lamp.
4. Once on the lamp, jump onto the ledge above.
Once up here, just jump any where in this red rectangle and you'll fall down to under Stormwind.
Just make sure you're at 100% health, because the fall will take around 50%.