You require 3 toons to request the task. There are see invis mobs so not easy to just run to the mob and kill it. With that said, did it today with a druid, shaman and bard. We cleared our way in with bard pulling and root rotted. Puled Gimblax with bard slow, and rooted it. Bard dotted til summoning started, to establish agro. Bard continued to dot and just move back when summoned. Druid focused on heals and shaman added slow and dots at a pace to let the bard maintain agro. Not a conventional way to kill but it worked well enough we will use that again. Took us about 3 hours from start to finish with a couple of restarts, as we were learning.