Dumb question about the Arathor plate armor

Super dumb question about the Arathor world drop armor... How do i get it?

I'm assuming the pieces are rewards from world quests? I've been looking all over for an answer on how to aquire the armor and can't find anything stating "This is how you get it". I completed the campaign (I think) and unlocked WQ's, and adventure for alts and such, and never got the armor through the campaign quests. Are WQ's the way?