How to remove light pollution in DPP4

[dpsaiz]

I was watching a video showing how to use Photoshop to remove light pollution.

I live in the fourth largest city in the US and there's no escaping light pollution unless I pack food, water and drive for several hours to escape it.

How can I do this with DPP 4? 

[kvbarkley]

What tool did they use in PS?

While you might be able to use some contrast enhancement to make the sky dark, it won't bring back the washed out stars.

[dpsaiz]

https://www.youtube.com/watch?v=D6FJvrI0PNA&t=16s