The instructions for arcade games is the same in Full and Score mode.
If you are playing this game Final Fight
» Coin Op
then in both modes all you do is
plug your controller in - you must do this before starting the game (you might want to use windows control panel to make sure the controller is recognized and working)
click one of the play mode links
the game will load up
after the game starts press tab
the menu will appear
use arrow keys and enter or the mouse to select different options
select "Input (general)" or "input (this game)". The first option changes controls for all coin-op games. The second changes it for just this game.
Select the control you want to change and then press the button you want to assign to that control.
exit out of the menu and you are finished.