You need to push the 'bottom' of the far-right switch to 'set or to decelerate'. The top of the far-right switch 're-sets to previous (while the cruise / ignition is on) or it increases speed AFTER being set. The small , single right button disengages without having to hit the brake. The far left button toggles the entire Cruise System on or off.
Typical use would be :
Push far left button to toggle the Cruise System 'on'.
Hold accelerator pedal with your foot to appropriate speed (usually over 40 mph is necessary).
While holding speed steady, push bottom of far right button to 'set'.
If deceleration to a constant speed with Cruise ON is desired, push and hold bottom of far right button until desired speed is attained.
Same procedure for increasing speed ,,just hold top of far right button in.
Mike in AR