the instructions are in the owners manual - pg 260 in '07 manual - it may take a couple tries to get it to work, but keep at it and you will succeed.
for those w/out a manual --
reset the maintenance minder as
Turn the ignition switch to the ON
Press the Select/Reset knob
repeatedly until the engine oil life
Press the Select/Reset knob for
about 10 seconds. The information
display shows the resetmode
initial display (as shown in manual).
Select the ‘‘OIL LIFE’’ indicator by
turning the Select/Reset knob.
The display begins to blink. Push
the same knob to enter this setting.
The engine oil life and the
maintenance item code(s) will
begin to blink. Push the Select/
Reset knob to reset.
The maintenance item code(s) will
disappear, and the engine oil life
will reset to ‘‘100.’’