To clarify the first reply, "turn the ignition all the way with out starting.
Press and depress the accelerator fully 3 times." means turning the key to the 'run' position and pressing the accelerator to the floor 3 times in a row. The change oil light will flash a couple of times and then it is reset. It will come back on after 5 or 6 thousand miles of normal driving. I had a vision of someone trying to push the pedal down 3 times real fast while the car is actually cranking (but before it starts).
The reset button was last seen on the 94 model year cars.
Just a gentle reminder though, this question has been asked about 14 million times and is easily found in a search of the forum. Repeating the question/answer only clogs up the archieves and makes it a longer search in the future for all queries.