Part 1
Best way to get to the centurion's is to enter the WQ from the road that leads into it and if you have coordinates /way 50.27, 22.94
As you come down the first part of the stairs the centurions will be off to the left and /way 50.10, 20.55 if you have coordinates.
Part 2
After you select your centurion it will appear into the generator and walk out and you will auto mount it.
Part 3
From here on out you'll be using abilities from the centurion and slay the forces in the area. I would suggest killing the mobs in the next step at around 75% so you can already have the path cleared.
Part 4
Next you will need to slay [npc=173575]. To get to them you'll go to the stairs you came down as you entered the area and go towards your left and you'll see another set of stairs. Go up those stairs and then follow the path straight and go to the left and you will see [npc=173575] down the mini stairs. If you have coordinates it will be /way 49.26, 16.01. Once you slay her you'll be ported back to the stairs with the WQ finished.
Coordinate Locations for TomTom/Paste:
/way #1533 50.27, 22.94 Centurions Assemble Entrance
/way #1533 50.10, 20.55 Centurion Selection
/way #1533 49.26, 16.01 Overseer Phoneira
Note: Used Zone # since Blizzard used Bastion multiple times and TomTom can't find the zone correctly.