Hi there,
First time contributing, I' ve searched for similar threads and none seemed to describe this way.
There might be other ways to do it but since the one using flying mount or the underbelly elixir in the sewers to get above the invisible wall got fixed I have thought it could be usefull. Engineering helps but is not required.
Tried it with a bear and it didn't work so I' ll asume you need a mammoth to do that.
And as a reminder the DC macro is no longer required since patch 3.3.3.
As for the video it seems that I can't link it because of mmowned restrictions so just search for dalaranarena.mp4 on youtube.
Enjoy.