That's a little system tray based app which lets you change alot of those settings, though in KDE control > Peripherals > Display the same options are in a little more detail.
HOWEVER, and i haven't worked this out myself yet for my system, i'm inclined to say that you might have to convince the X server that your system can run that refresh rate, and that would be where it gets complex.
Try the above if it doesn't do what you want, time to backup your /etc/X11/ directory and get aquainted with
(hours of fun, potentially weeks if you bungle it and fail to backup your config file)
Now you are heading down this road on your own, you can damage your monitor if you "overclock" it, beyond it's rating.