In the Order View screen press the track wheel and select Stop Order function from the side menu.
In the Stop Order screen, scroll down to the very bottom field and enter the necessary Stop rate changes. (In this case your Stop price must be higher than 120.63)
* Note: Since you are changing the Stop Order Rate, you now are given more options in the Stop Order screen side menu
SIDE MENU: OK

Once required field is filled in, press the track wheel and choose OK function from the side menu
When confirmed you will be redirected to the Order View screen for the order you have just worked with
Scroll down to the Stop field where you should be able to see the new Stop Order Rate you have just changed for this existing order
ORDER VIEW SCREEN