how can I choose the Theme pictures for Desktop Background

In W-7, I could go to the "Change the visuals and sounds on your computer" and click the "Desktop Background" Slide Show. once there, I could check or uncheck the pictures I wanted.
In W-10, when I click "Desktop Background", I get the "Background" "Preview" window. There's no handy access to the pictures in the selected screen.
The "Chose albums.....", DesktopBackground", Browse would probably get me to where the actual pictures are if I knew where they are.
It use to be very simple.
There are some pretty awesome themes but I don't like all the pictures in some of them.
Pete

Ok, Shawn, you did it again.
Either one of those "Run" commands:

rundll32.exe shell32.dll,Control_RunDLL desk.cpl,,@desktop
control /name Microsoft.Personalization /page pageWallpaper

get you to exactly what I am looking for.
Yet using the Control Panel or the Settings Personalization doesn't.

I don't know how you find this stuff. I've been an Insider since the first release and never saw anything like this.
Anyway, as usual, many thanks.
Pete