How do you turn off the perform service warning on a jeep?

try this, turn your key to run ( not start ) press the gas pedal down three times, then turn the key off. Turn the key to start and the light should be off.

To reset your service interval counter:
Turn the ignition on
Press the 'select' button momentarily then
Press the set button for at least 2 seconds
The counter will reset to 7500 miles