I don't have a JK but after perusing a owner's manual for an '08 I found the following:
"Change Oil Message"
Your vehicle is equipped with an engine oil change
indicator system. The “CHANgE OIL†message will flash
in the instrument cluster odometer for approximately 12
seconds after a single chime has sounded to indicate the
next scheduled oil change interval. The engine oil change
indicator system is duty cycle based, which means the
engine oil change interval may fluctuate dependent upon
your personal driving style.
Unless reset, this message will continue to display each
time you turn the ignition switch to the ON/RUN
position. To turn off the message temporarily, press and
release the Trip Odometer button on the instrument
cluster. To reset the oil change indicator system (after
performing the scheduled maintenance) refer to the following
procedure.
1. Turn the ignition switch to the ON position (Do not
start the engine).
2. Fully depress the accelerator pedal slowly three
times within 10 seconds.
3. Turn the ignition switch to the OFF/LOCK position.
NOTE: If the indicator message illuminates when you
start the vehicle, the oil change indicator system did not
reset. If necessary repeat this procedure."
Hopefully this is the same procedure for the '09's, as well.