The displayed service reminder is reset using the following procedure:
1) Turn the ignition to the OFF position.
2) Press and hold the TRIP button on the steering wheel.
3) Turn the ignition to the ON position, do not start the engine.
4) Release the TRIP button on the steering wheel.
Important : A confirmation beep will sound upon reset.
5) Once in the Service Reset screen, press and hold the ENTER switch (The LHS steering wheel scroll wheel) for 3-5 seconds.
If the service reminder comes back on when you start the vehicle, the Service Reminder Display has not reset. Repeat the above procedure.
Good work on changing the oil yourself. A lot of the corner mechanics just end up sticking some generic grade oil such as 20w50, or 15w40 in there without really checking the specs as to what the car needs.
There is a bit of info here as to how to reset the service reminder, as well as the oil life reading.
doc-holden-commodore-ve-oil-change-information-d47m19.html#9Hope this helps
Cheers matti