Resetting ARC Ref3 Tube Hours

Does anyone know how to reset the tube hour clock on the ARC Ref3?
I have the LS26 and PH7, both have internal clocks and can display hours in use.
The owners manual for both intructs the owner to call Audio Reaserch (have serial numbers ready) and they will instruct you how to reset.
Remove the top panel,with the aid of the manual locate the "door bell" press once and the counter resets to zero.
Anybody remember where the button is? I'm having trouble locating my manual.