For this achievement all you need to do is build a pillory and get one of your settlers into it. To build a pillory just go into any of your settlement areas, open your workshop with
, then go to resources then misc. Within the misc you will find the pillory. Once you have your pillory built find a random settler select him with
then go over to your pillory and select that with
aswell which should then assign your settler to the pillory and your achievement should pop.
If you would like a guide of how to find the pillory or a video guide for the whole achievement I have included my video guide below.