How to unassign dupe skill point?

How to unassign dupe skill point? - Muscular female dancer rehearsing in spacious studio

The first time I used the Oxygen-not included skills system I accidentally assigned a skill point at the wrong place.
How can that be undone?

oxygen-not-included

Pictures about "How to unassign dupe skill point?"

How to unassign dupe skill point? - Focused ballerina training in studio

How to unassign dupe skill point? - Unrecognizable graceful ballet dancer resting on floor

How to unassign dupe skill point? - From above of crop anonymous female ballet dancer in pointe shoes sitting on floor in dance studio

Borderlands 2 - How to get Infinite Eridium, Skill Points, and Rank/Tokens

Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.

Images: Andrew, Andrew, Kristina Polianskaia, Budgeron Bach