Onkyo M-504 Integra Want Replace lights in meters

Hello everyone .. I have a Onkyo M 504 one meter light is out I like to replace it ,, But i have no idea what size bulb or watts is needed , I did read a few post on the net , Everyone says to look on ebay for them , But i have not found anything,
I have been to parts express i have no idea what to order ,,
Any info will be great ,, Chris