This is actually simple to do. As soon as you are at the nether world, take a left past gnarl until you reach where you can buy minion cosmetics. From this point take a left into the bar looking area with minions around the tables and keep going forward. Once you reach the bar counter, to the right you should see a minion on a stage and to the left of him a stairwell. Take the stairwell up and all the way to the end, the place should be called abyssal overlook, stand at the edge until your achievement pops.
If you down vote please tell me why so i can improve.