You're going to need atleast 8 people before you're allowed inside (to search for two more parties of 8), but you can duty finder for it apparently. Still means finishing the "Legacy of Allag" quest first. After that, Duty Finder it up.
Thanks I'm done reading things on this patch. I doubt i'll do the satasha 15 or lv20 quest in the next 3 months I just keep putting it off. Back to old 1.0 achievements grinds for me.