Using the wildfire is probably the easiest way to take these down.
Edit: Also, afaik, you need a team of at least two people to destroy it. One person needs to distract the minions (I recommend debuffing first), while the other person attacks the core. Be aware that the pulse will kill you even if you're cloaked, although it only triggers if it sees you. So, make sure your teammate doesn't trigger it on accident and get you murdered. I was recently killed this way, when not everyone in the group cloaked at the same time.
Edit #2: Theoretically, a tank with paralyze could solo one of these over a period of time, but it'd be a lot of work for nothing, since wild tower drops have been de-emphasized.