This solution is based on El Cuervo Slash solution
first, you need the ability to enter "Berserk mode" - in order to do so, visit a Ripperdoc and buy an operating system that support Berserk. (Biodyne Mk.1 is the cheapest 7,500$ require body level of 6)
i suggest to look after the random "blue star" event on the map
usually the "enemies" in these event are busy fighting, and it's easy to knock them down.
create a manual save game!
Then try to knock down enemies - I used Gorilla arms which require ~4-5 quick hits to knocked down an enemy. stealth non-lethal take downs didn't work well for me.
check if the enemies are still alive (point at them with the cursor and make sure that it's red) if there are less than 2 alive, load your game and try again.
once you've got 2 enemies alive pile them together below climbable high place and make another different manual save
climb that high place and press
to activate the berserk and jump near the pile you've made.
if the achievement didn't pop - load your second save and try again.
please notice that when you load your second manual save, if you point with the cursor on the bodies they will appear dead (blue) - it is bug, they are still alive and you may get the achievement when you try it again.
Another possible bug, was that the Berserk didn't activate when i pressed
. The only workaround that i found was to load the first
manual save and do the whole thing again. (make sure that you can activate the berserk before you knock down enemies)