ReCore

There are two ways to trigger the instant extract, the first is by sneaking up to a Corebot and catch it off guard allowing you to kill it outright by performing an instant extract.

The second is to achieve a high enough combo and this will allow you to instant extract, it seems to be about a 5 times combo needed for this also small one shot kill enemies will get your combo up so use them to get it up then go after a Corebot.

When fighting Corebots keep an eye just below the health bar, this is where it tells you that you can extract. As soon as you see the words 'Instant Extract' click in the right stick and you will get the core and this achievement.