ok.
*Turn the unit off by holding down the volume knob. Let go.
*Hold down the EQ button. Let go.
*The deck will flip out, exposing the jack on the bottom (now leading) edge.
*Plug in your sensor, and hang it where your head would be, or wrap and clip it around the headrest.
*Click the knob on the right, and it'll begin beeping a countdown.
*Get outta the car, and hope it's quiet outside.
*Yes, it's okay to stick your ear on the window
*This would be a great opportunity to read the manual.
You'll hear periods of tapping from each woofer individually, and some pink noise of varying volume. It'll take a while, and when it's done you'll see 'AutoEQ Complete' on the display. Then you can get back in, unplug the sensor, and click the left button to turn it back on. Press the eject button to close the deck.
Voila! You'll prolly wanna turn the sub back up afterwards.