Your one-touch buttons, also called Multi-Purpose Keys (MPK) or Virtual Purpose Keys (VPK), are found on the sides of the LCD screen on your phone (shown below).
One Touch buttons on GXP2135
One Touch buttons on GXP2170
To change the layout or functionality of your one touch buttons, submit a request outlining the changes in as much detail as possible. Please be sure to outline whether the change is just to your extension, or to the entire office.