How to Change "Open With" to Nothing?

Basically, I installed a skin for Steam and I accidentally kind of put it to open with notepad.
It's a .style file.
I was wondering how I could change it back to the default/nothing.
Because now, my entire Steam skin basically looks like the default :P
Anyone that helps me gets nothing xD

Have a look at this tutorial.

How to Unassociate File Extension Types in Vista, Windows 7, and Windows 8
http://www.sevenforums.com/tutorials...associate.html
It was written for Vista, Win 7 and Win 8.
I think it is also applicable to Win 10.
It won't hurt your computer if it does not apply to Win 10.

Go to Option Three.