The 2016 Ford F-150 can come equipped with a convenient Integrated Tailgate Step. With the tailgate open, press the release button until the step pops out. Slide the step all the way out and lower it down. Grab the yellow handle, extend the bar all the way out until it clicks, and lift it until it locks into place.
To fold the step back in, first press the yellow number "1" button on the bar and telescope the handle.
Press the yellow number "2" button, lower the bar down to the horizontal position, and push it back into the tailgate. Now, lift the step up and push it into the tailgate until it clicks into place.