On the Naiko N-1402, and after hours of hair pulling:
Press Menu, go to overview, press 1 or 2 and, while still pressing them, press down on Menu. You should then get a console with tuning options, press menu again, and the tuning console will appear. The P+ and P- are up and down respectively, the Volume+ and Volume- are the "adjust". At the bottom "Store", use Volume+ or Volume- to store the settings.
John C
September 2007