Setting the shutter speed on d3100 in manual?

Okay, so i tried to ask this question before, but i guess i need to be more specific, lmao.
One, how do you get to manual mode on the nikon d3100?
And also, once you're there, how do you set the shutter speed?

See the dial on top of your camera that has a bunch of cute little pictures and also the letters P, A, S, and M? The "M" stands for "Manual." Once you are in Manual, you change the shutter speed by turning the wheel that falls under your thumb on the back of the camera near the top.

All that information is contained in the camera user manual.