Roger, Nothing pertaining to computers is simple–until someone shows you how to do it, then suddenly it’s “simple.” 

Anyway, find your photo, then right click “open” & you’ll see several options including “open in Paint,” which is what you should do.  Then when the Paint program opens your photo should be displayed.  Now look at the top left side of the page, where you see “crop, resize, rotate,” & select resize.  Next you’ll see a graphic which shows you how to resize in per cents, & reduce it as much as you want.  That’s the way it should work, but if it doesn’t, let me know.