This can be done once you have unlocked the "Dodge Counter" skill. When a melee enemy attacks you, press
at the right time to dodge, and a QTE will pop up. Press
when the two circles meet to incapacitate the enemy. You might need to do it more than once depending on the enemy's armor or health, but you'll know that he's incapacitated when there's a small skull icon above him.
Note that this achievement can be farmed (even after completing the game) with the same spawn point exploit that's used in this "Deadeye" solution for the Xbox 360 version
. All credit goes to Wrongway1985 for that one.
Instead of shooting down the enemies from the zipline, as that solution tells you to do, just wait for them to zip down to you. They will take out their machete so that you can incapacitate them. Just make sure you kill them at the bottom of the zipline and not on the top platform, otherwise they won't spawn there again.
Note that even if you have unlocked the "Dodge Kill" skill, you can still incapacitate if you time it correctly. Once the
icon appears, press the button to incapacitate. If you wait a split second longer until the icon is at its largest, you will kill him instead, which will not count against this achievement.