Select File > Settings > User > Button Assignments.
The Button Assignments dialog opens. The title bar identifies the open button menu.
Do one of the following:
Select a button assignment from the list box.
or
In the Buttons group box, turn on the Ctrl, Alt, and/or Shift check boxes and select the desired logical button from the Logical Button Drop-Down List.
In the Action text box, edit the key-in.
Click Save to save the changes in the open button menu and close the dialog.