Do you not have the manual?

In the M mode you can change F-Stop and Shutter. The camera defaults to change shutter with the scroller below the shutter button. To change the F-stop press/hold the button to the left fo the shutter button and rotate the scroller. The Function button on the left of the lens (on the body) you can program that to be whatever you want. Mine is either White balance or ISO.

Otherwise you have to hit the magnifying glass button (bottom left on the back) to switch settings on the display. You can change your photo quality, size, WB, ISO, Focus area, Auto focus, Metering, etc...