Find this place just to the left of the entrance in Orgrimmar, and take the path as shown. It will take a few tries as the terrain will stop you.
When you're at this position you have to jump across to a small ledge part on the other side. This will also take a few tries.
When you're across, simply walk up to the highest point (easier said than done, once again).
Now when you're at the top... the screen might be a bit unclear but you have to jump around the mountain while avoiding the slippery ledge below, else you'll have to start over.
You should end up here, now all you have to do is follow the path around.
When you come across a part looking like this, just walk up.
Keep going a little bit more and:
Voila, you're above Orgrimmar!
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