How do you adjust the size of the buttons in CCP for the MX-990? How do you change the button design that is selected when download your equipment?

For instance, when I downloaded the codes for my receiver, CCP automatically defaulted the buttons (size and shape and design) for the "tuner" function. I want to change that button to a different design/shape. Let's say from the defaulted square button to an oval button shape.

Step-by-step instructions would be helpful, or pointing me to the correct post would be useful as well.

Thanks!