After writing this thread I noticed that someone had already posted a similar one 6 months ago, this one still works after 2.4 though so I'll post it for any rogues interested in an easier way.
The necessary requirements for our journey are the following:
1. Access to a +60 Shadowstep Rogue.
2. Access to a slowfall effect such as Noggenfogger elixir.
3. Access to the last boss of the Hellfire Ramparts
Our travel begins at the entrace of this place, there are a few stealth-detecting level 60 mobs in our way, but nothing a level 70 rogue easily can't handle.
Standing down beneath Vazruden the Herald, the destination of our journey can be seen close at hand in the background.
A quick Shadowstep and we're here, sitting on the wall of emptiness.
Gliding down the wall, we have arrived.
The great widths of Hellfire Peninsula await us.
The instanced version of this zone extends from Honor Hold in the southeast to the Mag'har Post in the northwest, happy exploring.